Browse Topic: Acoustics

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An analysis of material damping characteristics: A comparison of Oberst Bar Method and Center Impedance Method and their relationship to Component Level.2026-26-0317To be published on 01/16/2026
Damping materials exhibit advantageous mechanical and acoustic characteristics that enhance the structural integrity of systems. These materials find extensive applications across various industries, including automotive, aerospace, and building acoustics, and are widely employed in the development of soundproofing materials. The damping characteristics of materials primarily pertain to the dissipation of vibrational energy, the reduction of oscillations, and the controlling and subsequent attenuation of vibration-induced noise emanating from structures. To improve both structural integrity and acoustic performance, it is crucial to accurately assess the damping properties of these materials. The Oberst bar test method is a standard method used in the automotive, railway and building industry for initial optimization of damping material However, questions have arisen about the degree to which the outcomes of the Oberst test truly reflect real-world applications. Numerous experimental
Kamble, Prashant Prakash, Joshi, Manasi, Jain, Sachinkumar
Simulation based optimization of the NVH characteristics in modern high speed engine during development phase2026-26-0326To be published on 01/16/2026
Engine noise mitigation is paramount in powertrain development for enhanced performance and occupant comfort. Identifying NVH problems at the prototype stage leads to costly and time-consuming redesigns and modifications, potentially delaying the product launch. NVH simulations facilitate identification of noise and vibration sources, informing design modifications prior to physical prototyping. Early detection and resolution of NVH problems through simulation can significantly shorten the overall development cycle and multiple physical prototypes and costly redesigns. During NVH simulations, predicting and optimizing valvetrain and timing drive noise necessitates transfer of bearing, valve spring, and contact forces to NVH simulation models. Traditional simulations, involved continuous force data export and NVH model evaluation for each design variant, pose efficiency challenges. In this paper, an approach for preliminary assessment of dB level reductions across design iterations is
Rai, Ankur, Deshpande, Ajay Mahadeo, YADAV, RAKESH
Prediction of Trimmed BIW Noise transfer function based on BIW response using Machine Learning2026-26-0640To be published on 01/16/2026
This research focuses on the prediction of the Noise Transfer Function (NTF) in a trimmed Body-in-White (BIW) structure by leveraging machine learning technique considering BIW-level NTF, dynamic stiffness at engine mount attachment points, and Vibration Transfer Function (VTF). The study employs an iterative methodology, adjusting the thickness of various BIW panels to analyse their impact on noise transfer characteristics. Frequency response functions are generated at the BIW attachment points to assess the effectiveness of these modifications. By systematically increasing and decreasing panel thicknesses, and stiffness at the attachment point and trimmed BIW level responses the study aims to optimize the acoustic performance of the BIW structure. The findings provide critical insights into the relationship between structural modifications and noise transfer, offering valuable guidance for automotive design and engineering during early design stage to reduce the development time.
Kulkarni, Prasad Ramesh, Bijwe, Vilas, Kulkarni, Shirish, Sahu, Dilip, Inamdar, Pushpak
Development of a GUI-Based Pitch Sequence Optimization Tool for Tyre Noise Reduction2026-26-0330To be published on 01/16/2026
Minimizing tyre noise is essential for enhancing ride comfort, especially in electric vehicles where the absence of engine noise makes tyre-generated sound more prominent. This work presents the development of a GUI-based pitch sequence optimization tool to support tyre design engineers in generating acoustically optimized tread sequences. The tool operates in two modes: without constraints, where the pitch sequence is optimized freely to reduce tonal noise levels; and with constraints, where specific design rules are applied to preserve pattern consistency and manufacturability. This tool plays a pivotal role in the tire development process, serving as one of the key evaluation criteria for tread pattern approval before mould fabrication. By enabling engineers to generate balanced, low-noise pitch sequences that align with both acoustic targets and engineering constraints, the tool facilitates faster design iterations and smooth integration with downstream processes. Its successful
Sampathraghavan, Lakshmi, Ramarathnam, Krishna Kumar, Mantripragada PhD, Krishna Teja, Ramachandran, Neeraj
Strategic Design of Intake Systems for Crafting a Sporty Acoustic Signature in Passenger Vehicles2026-26-0328To be published on 01/16/2026
In pursuit of a distinct sporty interior sound character, the present study explores an innovative strategy for designing intake systems in passenger vehicles. While most existing literature primarily emphasizes exhaust system tuning for enhancing vehicle sound quality, the current work shifts the focus toward the intake system’s critical role in shaping the perceived acoustic signature within the vehicle cabin. In this research work, target cascading and settings were derived through a combination of benchmark and structured subjective evaluation study and aligning with literature review. Quantitative targets for intake orifice noise was defined to achieve the desired sporty character inside cabin. Intake orifice targets are engineered based on signature and sound quality parameter required at cabin. Systems are designed by using advanced CAE techniques, Specific identified acoustic orders were enhanced in the intake system to reinforce the required signature in acceleration as well
Sadekar, Umesh Audumbar, Titave, Uttam, Patil, Jitendra
Measurement of Acoustic Sensitivity of Automotive Drum Brake to Multiple Faults2026-26-0555To be published on 01/16/2026
Multiple faults can occur over time in drum brakes, which are commonly used on the rear of heavy vehicles and two-wheelers, compromising passenger safety and ergonomics. Given the recent success of artificial intelligence in fault diagnosis, it can be applied effectively to automotive brakes during operation when combined with advanced measurement techniques. However, monitoring the brake health during operation is challenging due to the rotational motion of components and space constraints for sensors. Consequently, this study investigates the use of measured radiated noise from drum brakes (instead of vibrations) to detect faults. A test bench mimicking typical on-road braking dynamics has been developed to operate in a controlled environment with pre-determined fault levels. This setup measures acoustic signals during transient brake events. Acoustic responses from several experiments that imitate three common brake fault conditions are measured. The acoustic sensitivity to each
Shripad, Kumar Milind Rewanand, Yella, Akash, Sundar, Sriram
An Engineering Perspective on Cradle and Saddle Mount Configurations2026-26-0313To be published on 01/16/2026
The evolution of electric vehicles (EVs) demands optimized powertrain mounting systems to achieve superior Noise, Vibration, and Harshness (NVH) performance. This study presents a comparative evaluation of cradle-type and saddle-type mounting systems in EV applications. Experimental modal analysis and vehicle-level vibration testing were conducted to assess structure-borne and airborne noise transmission across operating conditions. Key factors such as mount stiffness, isolation efficiency, and dynamic load distribution were analyzed. Cradle systems exhibited better low- to mid-frequency isolation, whereas saddle systems offered advantages in packaging flexibility, high-frequency noise control, and reduced load distribution on supporting structures. These findings provide valuable guidance for selecting optimal mount strategies to enhance occupant comfort and acoustic quality in future EV designs. Recommendations for mount system improvements considering evolving EV architectures are
Hazra, Sandip, more, Vishwas, Naik, Sarang Pramod
JAX9900JAX9900_202512 (Current)12/04/2025
JAX9900
Active Safety Systems Standards Committee
Verifying large alternate product code for an JA GV document - JA1124XXJA1224XX/NEW/00000000000000000001_202511 (Current)11/24/2025
Verifying large alternate product code for an JA GV document - JA1124XX
Active Safety Systems Standards Committee
Implementation Of Machine Learning In Acoustics Source Detection by Leveraging Synthetic Sound Data Generation Approach2024-26-021301/16/2024
E-Mobility and Low Noise IC Engines has pushed product development teams to focus more on sound quality rather than just focus on reduced noise levels and legislative needs. Further more qualification of products from a sound quality perspective from an end of line testing requirement is also a major challenge. End of line (EOL) NVH testing is key evaluation criteria for product quality with respect to NVH and warranty. Currently for subsystem or component level evaluation, subjective assessment of the components is done by a person to segregate OK and NOK components. As human factor is included, the process becomes very subjective and time consuming. Components with different acceptance criteria will be present and it’s difficult to point out the root cause for NOK components. In this paper, implementation of machine learning is done for acoustic source detection at end of line testing. To improve the fault detection an automated intelligent tool has been developed for subjective to
Shukle, Srinidhi, Iyer, Ganesh, Faizan, Mohammed
Methodology for jury evaluation and target setting for passenger vehicle operational sound quality2024-26-022701/16/2024
In automotive market, with competitive car prices, build quality of a car will be a major distinguishing factor. Consumer's need for acoustic comfort has evolved from the removal of annoying noises to perceived sound quality. Operational sounds from electromechanical systems like sunroof system, window regulator, door lock system, HVAC etc. directly interact with users' senses. The perceived acoustics comfort of these sounds are direct indicators of vehicle character and can influence customer's buying decision. With the reduction in product development time and stringent cost constraints, a proper structured target setting methodology to benchmark & evaluate these operational sounds is crucial. In this paper, such a target setting methodology is proposed and discussed for operational sound quality evaluation. Electromechanical noises from various vehicles are measured using binaural head measurement system. Using Simultaneous Categorical Scaling method, jury evaluation is performed
Somasundharam, Sundaralingam, Manoj K, Mridul, RAJ, GAURAV, Mohammed, Riyazuddin, R, Prasath
Challenges for Indian Road Traffic with Sound Alert Devices on Electric Vehicles2024-26-021101/16/2024
Challenges for Indian Road Traffic with Sound Alert Devices on Electric Vehicles For safety towards pedestrians and other road-vehicles, sound alert systems (horns) have been in use since development of Automobiles. On the same line but with special purpose of preventing a Driver to sleep in a running vehicle, a Driver Monitoring System [DMS] is recently developed. For Electric Vehicles which are very quiet during starting and driving till 20 km/hr, Acoustic Vehicle Alert System (AVAS) is deployed in Europe and likely to be implemented in India soon. For all these Alert Devices, there are Standard Regulations across the world: ECE R-28 for Horns and ECE R-138 for AVAS. They, however, define only lower and upper dBA limits of the sound radiated by them. For DMS, no such regulation exists till today. With this, there has been a long time debate on what an optimal dBA level should be there, for all road-users as well as for vehicle- users inside the cabin. It would be adequate, on one
A, Milind Ambardekar
Achieving New Pass-By Noise Regulatory Norms R51.3 (Method B) - An Analysis of Acceleration and Noise Source Contribution2024-26-019901/16/2024
Worldwide automotive sector regulatory norms have changed and become more stringent and complex to control environmental noise and air pollution. To continue this trend, the Indian Ministry of Road Transport is going to impose new vehicle exterior pass-by noise regulatory norms R51.3 (Method B) in the upcoming year to control urban area noise pollution. This paper studies the synthesis of M1 category vehicle driving acceleration, dominant noise source, and frequency contribution in exterior PBN level. A vehicle acceleration analysis study was carried out to achieve an optimized PBN level based on the vehicle’s PMR ratio, reference, and measured test acceleration data. Based on the analysis, the test gear strategy and acceleration were changed to achieve a lower PBN level. Improved engine calibration resulted in a 20% increment of ith gear acceleration. This increased acceleration surpassed the upper limit of the reference acceleration range; hence, the vehicle was tested in a
kalsule cEng., Shrikant Balasaheb, Titave, Uttam, Patil, Jitendra, Jadhav, Kamalakar, Naidu, Sudhakara
A Simulation methodology to design the AVAS system to meet safety regulations and create the expected perception for the vulnerable road user2024-26-023001/16/2024
"Designing an effective AVAS system, not only to meet safety regulations, but also to create the expected perception for the vulnerable road user, relies on knowledge of the acoustic transfer function between the sound actuator and the receiver. It is preferable that the acoustic transfer function be as constant as possible to allow transferring the sound designed by the car OEM to ensure the safety of vulnerable road users while conveying the proper brand image. In this paper three different methodologies for the acoustic transfer function calculations are presented and compared in terms of accuracy and calculation time: classic Boundary Element method, H-Matrix BEM accelerated method and Ray tracing method. An example of binaural listening experience at different certification positions in the modeled simulated space is also presented."
Calloni, Massimiliano, Hadjit, Rabah, Salvekar, Pinak, Musser, Chadwyck
Cabin noise modeling for seat location variation using AI and Machine Learning2025-01-012905/05/2023
Analyzing acoustic performance in large and complex assemblies, such as vehicle cabins, can be a time-intensive process, especially when considering the impact of seat location variations on noise levels. This paper explores the use of AI and machine learning to streamline this analysis by predicting the effects of different seat configurations on cabin noise, particularly at the driver’s ear level. The study begins by establishing a baseline simulation of cabin noise and generating training data for various seat location scenarios. This data is then used to train an AI model capable of predicting the noise impact of further seat adjustments. These predictions are validated through detailed simulations. The paper discusses the accuracy of these predictions, the challenges encountered, and provides insights into the effective use of AI and machine learning in acoustic analysis for cabin noise, with a specific emphasis on seat location as a key variable. Keywords: Acoustic analysis, AI
Kottalgi, Santosh, Banerjee, Bhaskar
Sound quality centered measurement technique over 40+ years: experiences and perspectives2025-01-007305/05/2023
The author’s life work in acoustics and sound quality, though continuous over more than 40 years, has followed a number of parallel and nonparallel paths all involving measurement technologies and their evolution. The illustrated discussion begins at the Research and Development Division of Kimball International, Inc. (Jasper, Indiana) in 1976 with piano research using a Federal Scientific Ubiquitous analog real-time FFT analyzer and Chladni-plate-mode studies with fine sand and high-speed photography of sound board modes excited by various notes and damper pedal positions. It continues at Jaffe Acoustics, Inc., a concert-hall-specializing consultancy in Norwalk, CT, with early-reflection plotting using a parabolic microphone on an altazimuth angular-readout mounting and either photographing oscillograms, or running a high-speed paper chart printer, assembling “wheel plots” incremented every 10 degrees in azimuth and altitude to map reflection patterns. Involvement with binaural
Bray, Wade
Acoustic characterization of AC motor using sound intensity in standard laboratory environments2025-01-001005/05/2023
Sound power is commonly used metric to quantify acoustic sources like AC motor in electrified powertrain. This testing is often performed in an anechoic environment to create free-field conditions around the unit. To eliminate the influence of extraneous noise sources, the anechoic facilities must be further isolated from driver and absorber dynamometers. These dynamometers are needed for running the AC motors in the desired speed and load conditions. For early detection of potential issues, it is advantageous to have the capability for engineers to conduct acoustic tests in standard laboratory environments. These may include non-acoustically treated rooms, presence of extraneous noise sources (e.g., driver and absorber dynos), etc. In such environments, sound intensity-based sound power determination methods could be utilized. The sound intensity-based approach is covered in ISO 9614 standard. The norm is to sweep an intensity probe on a sound source in constant speed condition to
Kumar, Aditya, Ippili, Rajani
Characterization and Prediction of Interior Noise Quality in Electric Vehicles through Drive Unit End-of-Line Testing (EOLT)2025-01-003905/05/2023
This paper addresses the critical aspect of interior noise quality in electric vehicles (EVs), focusing on the characterization and prediction methodologies employed during drive unit end-of-line testing. The electric drive unit plays a pivotal role in determining the overall Noise, Vibration, and Harshness (NVH) quality of the final product. This study explores the impact of drive unit assembly process variation and individual component tolerance on the NVH characteristics of electric drive units, emphasizing their direct effect on overall vehicle acoustic quality and customer comfort. The research delves into the intricate relationship between drive unit vibrational response, vehicle interior noise, and customer subjective perception, providing valuable insights into their correlation and how they collectively influence user experience and satisfaction. It aims to enhance the understanding of how electric drive unit characteristics contribute significantly to the interior noise
Arvanitis, Anastasios, Parbat, Aniket, Jadhav, Prashant, Raphael, Andrew
A study on active sound design and control method for vehicle interior hybrid noise to enhance sound quality2025-01-001105/05/2023
With the current popularity of new energy vehicles and the continuous development of intelligent cabin technology, the demand for acoustic comfort within automotive cockpit is increasing. A multi-channel feedforward active sound design and control method was proposed to improve the sound quality of the hybrid broadband and narrowband noise inside the test vehicle. The method selectively designed the target amplitudes for broadband noise and narrowband noise in the vehicle to satisfy passengers comfort, mainly including the sound design phase and the control phase. During the sound design phase, objective sound quality parameter analysis was first conducted on the noise of the prototype vehicle, followed by an evaluation of the sound quality with semantic differential method. An active acoustic design strategy focusing on comfort, motivation sense and annoyance perception were proposed, including a formula for the target amplitude of adjustment order and sound pressure level. The sound
Liu, Xuexian, Xu, Wenxuan
Effects of acoustic dissipative material in applications with acoustic leakage2025-01-011705/05/2023
In the paper, the dissipative material and other conventional acoustic materials are studied in conditions which simulates actual vehicle application with acoustic leakage. The various acoustic materials are evaluated in the lab with acoustic leakage existing in steel panel experimentally and virtually in computer simulation with the estimated Biot’s parameters of the materials. Often, the acoustic leakages exist in actual vehicle condition in pass-through or mounting faster locations. The work includes in-vehicle test results on application and show how the dissipative material works.
Yoo, Taewook, Maeda, Hirotsugu, Sawamoto, Keisuke, Anderson, Brian, Gan, KimTong, Herdtle, Thomas
High-resolution option for the Sottek Hearing Model Tonality enables accurate order analysis2025-01-009305/05/2023
The Sottek Hearing Model provides a comprehensive framework for understanding the nuances of sound perception, including such aspects as loudness, tonality, roughness, fluctuation strength, sharpness, and impulsiveness. The principal model was first published more than three decades ago as part of a doctoral thesis. Over the past few decades, the model has been refined and recently standardized in the international standard ECMA 418-2. This standard addresses several psychoacoustic parameters, including a new approach to time-varying loudness based on a nonlinear combination of partial tonal and noise loudness. This is the preferable approach because the loudness of tonal components (i.e., tonal loudness) may have a more pronounced impact on loudness perception than the loudness caused by other components (i.e., noise loudness). Other standardized parameters include tonality and psychoacoustic modulation analyses. These comprise roughness, which is employed to evaluate rapidly
Sottek, Roland, Bray, Wade
The applications of Acoustic Black Holes to attenuation of Coach/Bus Frame Structure Vibrations2025-01-006505/05/2023
Abstract An acoustic black hole (ABH) is a structure whose cross-sectional thickness decreases exponentially to zero, and the phase velocity and group velocity of wave propagation in those structure acoustic black holes decrease as the thickness decreases until they are zero. ABH produce some very magical physical phenomena. For example, because the wave velocity decreases to zero, the wave can never reach the center of the ABH, so the wave propagation in the acoustic black hole has neither refraction nor reflection; that is to say the vibration wave will not go through the acoustic black hole. As a result, the wave energy is concentrated in the center of the ABH. The arrangements of those acoustic black holes in the structures could change the directions of the vibrational wave propagation in the structures at NVH engineers’ wills. These amazing phenomena could play a magical role in reducing structural vibration, structural noise radiation and structure-borne noise. Basic structures
Huang, Xianli
Directivity driven simulation methodology for efficient Acoustic Encapsulation2025-01-004805/05/2023
Noise Reduction at the source level is critical to achieve the overall vehicle level interior targets. This method presents a novel approach that integrates directivity analysis with simulation techniques to optimize acoustic encapsulation design for automotive sound sources to achieve the targeted radiation levels. The foundation for this methodology is to measure the angular distribution of sound pressure levels around the noise source so called Directivity, at every frequency of interest and determine the most effective Acoustic encapsulation to achieve the targeted sound radiation. Accurate measurement of directivity in physical testing with fine angular resolutions can be complex and expensive, this study utilizes numerical simulation techniques using FEA to mitigate the challenges in mid frequency range. The scope of the study is focused on mid frequency sound pressure levels between 500-2000 Hz, which are determined to be significant contributors to overall DU noise. The first
KALUVAKOTA, SRIKANTH, Ghaisas, Nikhil, Pilz, Fernando
Tonal noise investigation of automotive HVAC systems : a hybrid method2025-01-002705/05/2023
There is no need to recall how the electrification trend of transport facilities has tightened the requirements around acoustic comfort. Within the automotive industry, these targets are more challenging for Heating, Ventilation and Air Conditioning systems for which passengers are in the foreground of noise emissions. The complexity of the requirements and specifications set by car manufacturers and suppliers stems from a dual aspect. First is quantitative based on the sound pressure level, whether it's the overall level or 1/3 octave band spectra. The second is purely subjective based on the perceived noise quality by stakeholders and final customers worldwide. During development phases, low frequency tone noises are frequently encountered on these systems which might induce discomfort to the passengers. The experimental investigations usually point to an aerodynamic origin, which prompted this research activity. The purpose of this work is to analyze and understand the mechanism of
Bennouna, Saad, Alaoui, Mohamed
Prediction and Optimization of Noise radiation from a Heavy-Duty Commercial Vehicle Transmission using Statistical Energy Analysis2025-01-005105/05/2023
Heavy Duty (HD) linehaul vehicles are majorly used in transportation of goods and heavy loads between different cities or long distances. Considering the current trend, payload capacity of these heavy-duty trucks are increasing due to constant increase in the load demand. Due to which engine torques of these HD vehicles are increasing which in turn increases the transmission input torque. At higher torque levels, gear excitation also increases and transmission becomes more susceptible towards higher noise radiation. Global vehicle pass-by noise regulations for HD commercial vehicles are becoming more stringent. Historically transmissions have been considered a secondary noise source but with overall HD vehicle noise becoming quieter, the transmission can be more of a significant noise contributor. Hence, noise radiation from the transmission is also an important factor to be considered in the design phase. Gear whine is the major concern for sound radiation from the transmission. The
Rastogi, Sarthak, Milind, T. R.
Evaluation of Automotive Closure Design for High Frequency Acoustics Performance2025-01-004905/05/2023
A good NVH environment in a vehicle plays an important role in attracting a large customer base in the automotive market. Hence, NVH has been given significant priority while considering automotive design. NVH performance is monitored using simulations early during the design phase and testing in later prototype stages in the automotive industry. Meeting NVH performance targets possesses a greater risk related to design modifications in addition to the cost and time associated with the development process. Hence, a more enhanced and matured design process involves Design Point Analysis (DPA), which is essentially a decision-making process in which analytical tools derived from basic sciences, mathematics, statistics, and engineering fundamentals are used to develop a product model that better fulfills the predefined requirement. This paper shows the systematic approach of conducting a Design Point Analysis-level NVH study to evaluate the acoustic performance of vehicle door systems in
Ranade, Amod A., Shirode, Satish, Miskin, Atul, Mahamuni, Ketan, Shinde, Rahul, GHAN, PRAVIN, Choudhury, Ashok
Evaluation of invariant structural and acoustic loads estimation methods to be used in vehicle platform development independent to the boundary conditions of load generation.2025-01-005305/05/2023
Platform based vehicle development is standardized at Deere. The challenges of frontloading the integration effects of individual components within different platforms using predictive methods is key to shorten the development cycle. Components are generally characterized on test benches and can not directly be used to evaluate system performance. Invariant characterization is needed which is possible through techniques such as blocked loads estimation. To evaluate the applicability of such methods, the test stand based, and vehicle in-situ operational loads needs to be compared. The confident use of these methods for structural and acoustic loads enables the use of combination of test and simulation models of common components and system modules in a variety of products, enhancing early NVH response predictions. In this work, we compare a powertrain characterization in a vehicle and a test stand to assess the invariance of the operating mount structural loads as well as operating
Vesikar, Prasad Balkrishna, Edgington, Jason, Drabison II, John, Chaduvula, Prasanna
Metamaterial application to automotive glass for vibration reduction and reduced noise transmission2025-01-011905/05/2023
A metamaterial which, attached to the edge of a panel, reduces vibration results in reduced noise transmission into a vehicle. In this particular case, the metamaterial is designed to be attached to the edge of a glass panel and can reduce panel vibration and noise transmission due to wind or other sources into the vehicle interior. Acoustic transmission loss and panel vibration assessments show the benefit of this approach.
Sorenson, Steve, Moore, Jaime, Robison, Scott, Li, Xiaopeng
Feasibility of In situ vehicle level transmission loss measurement to guide dash pass through grommet selections2025-01-012205/05/2023
Noise transmission through the vehicle dash panel plays a critical role in isolating passengers from noise sources within the motor bay of the vehicle. Grommets containing electrical harness routing as well as HVAC lines are examples of dash panel pass throughs that should be selected with care. Acoustic performance of these components is generally characterized in terms of measured quantities such as noise reduction (NR), sound transmission loss (STL), and Insertion Loss (IL). These measurements need to be carried out as per SAE or ASTM standards in appropriate anechoic or reverberant chambers as this is important for consistency. This work explores an in-situ vehicle measurement setup utilizing a repurposed vehicle cabin designed to serve as an anechoic chamber with its frunk acting as a reverberant chamber. This in-situ setup method is then compared to results following standards to discuss the differences in results. The data is studied to understand if there are any advantages to
Joodi, Benjamin, Jayakumar, Vignesh, Chang, Michael, Geissler, Christian, Pilz, Fernando, Conklin, Chris
Localisation of Ultra-short Sound Emissions from Automotive Components by Using the Sound Field Scanning Method2025-01-009205/05/2023
Design verification and quality control of automotive components require the analysis of the source location of ultra-short sound events, for instance the engaging event of an electromechanical clutch or the clicking noise of the aluminium frame of a passenger car seat under vibration. State-of-the-art acoustic cameras allow for a frame rate of about 100 acoustic images per second. Considering that most of the sound events introduced above can be far less than 10ms, an acoustic image generated at this rate resembles an hard-to-interpret overlay of multiple sources on the structure under test along with reflections from the surrounding test environment. This contribution introduces a novel method for visualizing impulse-like sound emissions from automotive components at 10x the frame rate of traditional acoustic cameras. A time resolution of less than 1ms eventually allows for the true localization of the initial and subsequent sound events as well as a clear separation of direct from
Rittenschober, Thomas
Do EVs Snore?2025-01-007405/05/2023
As EV and PHEV adoption continues to increase more people will have direct experiences with these quieter vehicles in their daily lives. Topics such as 'propulsion sound' via Active Sound Design (ASD) and bystander safety through Acoustic Vehicle Alerting Systems (AVAS) have been discussed widely for many, many years...but who is talking about Charging Noise? Charging noise is a less spoken about topic because most EV / PHEV owners will charge their vehicles at their home, in their garage or their driveway, overnight when they are sleeping. Because of that people do not think much about charging noise. But anyone who has plugged in their car overnight will tell you a strange cacophony of sounds come from the car...and some can be downright concerning. In this paper data from several production EVs were measured during their normal charging cycle. Binaural recordings made inside and outside the vehicle are analyzed using psychoacoustics metrics to see what sounds would cause the most
Marroquin, Marc, Bray, Wade
Application of Hybrid SEA in Vehicle NV Package Optimization2025-01-005005/05/2023
As India’s economy expands and road infrastructure improves, the number of car owners are expected to grow substantially in the coming years. This market potential has intensified competition among original equipment manufacturers (OEMs) to position their products with a focus on cost efficiency while delivering a premium user experience. Noise and Vibration (NV) performance is a critical differentiator in conveying a vehicle's premiumness, and as such, NV engineers must strategically balance the achievement of optimal acoustic performance with constraints on cost, mass, and development timelines. Traditionally, NV package optimization occurs at the prototype or advanced prototype stage, relying heavily on physical testing, which increases both cost and time to market. Furthermore, late-stage design changes amplify these challenges. To address these issues, this paper proposes the integration of Hybrid Statistical Energy Analysis (HSEA) into the early stages of vehicle development
Rai, Nitesh, Mehta, Makrand, Ravindran, Mugundaram
Characterize the Sound Field Generated from a Vehicle Horn by Pellicular Analysis2025-01-005805/05/2023
To predict the sound field produced by a vehicle horn requires a good source representation of it in the full vehicle model. This paper investigates the characterization of a physical vehicle horn by an inverse method called pellicular analysis. To implement this method, firstly an acoustic testing is performed to measure the sound pressure radiated from the horn at a certain number of microphone locations in a free field environment. Based on the geometry of a virtual horn, the locations of each microphone and measured sound pressure data, pellicular analysis is adopted to recover a set of vibration pattern of the virtual horn. The virtual horn and the recovered vibration information are then incorporated in a full vehicle numerical model to simulate its exterior sound field. The validity of this approach is confirmed by comparing the prediction for a horn in a production vehicle to the corresponding physical test which is required to meet the Brazilian regulation CONTRAN 764/2018.
Yang, Wenlong, MELO, ANDRE
Subjective development of EV propulsion noise to drive product differentiation2025-01-006705/05/2023
The frequency and amplitude content of powertrain noise is motor torque and speed dependent and tends to influence the driver’s subjective perception of the vehicle. This provides manufacturers with an opportunity to drive product differentiation through consideration of powertrain noise in early stages of the development cycles for electric vehicles (EVs). This paper focuses on evaluation of customer perception to acoustic feedback of motor design options based on targeted motor orders and expected wind and road masking during high acceleration maneuvers. A jury study is used to explore the customer feedback response to a two-stage gearbox design with AC permanent magnet motor order combinations. The subjective influence of order spacing, dominant frequency content and the number of audible tones is studied to understand aural perspective product differentiation opportunities.
Joodi, Benjamin, Jayakumar, Vignesh, Conklin, Chris, Pilz, Fernando, Iyengar, Shashank, Weilnau, Kelby, Hodgkins, Jeffrey
Hybrid 3D Sound Intensity and Simulation for Optimizing Acoustic Output of Truck Rear Axles2025-01-010505/05/2023
This study presents a novel methodology for optimizing the acoustic performance of rotating machinery by combining scattered 3D sound intensity data with numerical simulations, focusing on the rear axle of a truck. Using Scan&Paint 3D, sound intensity data is rapidly acquired over a large spatial area with the assistance of a 3D sound intensity probe and infrared stereo camera. The experimental data is then integrated into far-field radiation simulations, enabling detailed analysis of the acoustic behavior and accurate predictions of far-field sound radiation. This hybrid approach offers a significant advantage for assessing complex acoustic sources, allowing for quick and reliable evaluation of noise mitigation solutions. While the current application focuses on the truck's rear axle far-field radiation, the same method can be extended to predict in-cabin sound pressure, providing a versatile solution for many industrial problems.
Fernandez Comesana, Daniel, Vael, Georges, Robin, Xavier, Orselli, Joseph, Schmal, Jared
Sound Design for Electric Vehicles: Enhancing Safety and User Experience Through Acoustic Vehicle Alerting System (AVAS)2025-01-006805/05/2023
Silent engines are an excellent strategy to combat noise pollution. Still, they can pose risks for pedestrians who rely on auditory cues for safety and reduce driver awareness due to the absence of the familiar sounds of combustion engines. Sound design for silent engines not only tackles the above issues but goes beyond safety standards towards a user-centered approach by considering how users perceive and interpret sounds. This paper examines the evolving field of sound design for electric vehicles (EVs), focusing on Acoustic Vehicle Alerting Systems (AVAS). The study analyzes existing AVAS, classifying them into different groups according to their design characteristics, from technical concerns and approaches to aesthetic properties. Based on the proposed classification, an (adaptive) sound design methodology, and concept for AVAS are proposed based on state-of-the-art technologies and tools (APIs), like Wwise Automotive, and integration through a functional prototype within a
Esteves, Raquel, Campos Magalhães, Eduardo Miguel, Bernardes, Gilberto
Fast noise prediction of an electric powertrain integrated in various vehicles2025-01-007605/05/2023
The automotive industry's transition to electrification raises new challenges to maintain a comfortable acoustics environment both inside and outside the car. This paper presents an innovative way to make an early prediction of the overall sound of a vehicle at driver’s ear by mixing noise sources that can be simulated and noise sources that can be measured at component level. This hybrid approach combining Test and Simulation data helps make decisions in the early design phase by predicting the noise of one component integrated in the whole vehicle. For instance, Valeo, with the help of sound synthesis techniques, is able to predict the sound of an e-drive when it is combined with Rolling noise that varies depending on the vehicle speed and the car segments - more or less refined, from a dataset of multiple vehicles. Realistic signals could be generated and compared with actual acoustic measurement to validate the method.
Redon, Milan, Dendievel, Clement, Pluton, Matthias
Acoustic Evaluation of Fiber Based Materials for Engine Bay Applications2025-01-011505/05/2023
A newly formulated fiber-based material was developed to offer a cleaner, recyclable alternative to foam-based vehicle acoustic products. The fiber-based material was designed to be used in multiple vehicle acoustic applications, with different blends of the material available depending on the application. It performs well as an engine bay sound absorber due to its high heat tolerance and good absorption performance. A study was conducted to evaluate the sound absorption performance of this fiber-based material, specifically the engine bay blends, in comparison to that of current foam-based products. The results from this study show that the sound absorption performance of this new fiber-based material can match that of current foam-based materials while providing a recyclable product unlike the foam.
Krugh, Jack
Active Control of Engine Order Noise for Heavy-duty Trucks: Using the Genetic Algorithm for the Optimization of Error Microphone Arrangement2025-01-001305/05/2023
The arrangement of error microphones for a vehicle active noise control (ANC) system is no trivial work, especially for heavy-duty trucks due to the dilemma resulted from the large volume of the cab and the limited number of microphones accepted by most manufacturers in the auto industry. Most ANC developers resort to trial and error, which is not only a heavy workload given the amount of interested working conditions to be test, but also does not guarantee to yield the optimum noise cancellation performance. In this paper, the authors proposed an error microphone selection methodology using a genetic-algorithm (GA) -based mechanism. The target vehicle was a heavy-duty truck with a six-piston diesel engine, and two scenarios were particularly interested, i.e. driver & copilot and driver & one passenger sleeping on the berth. We first arranged eight microphones at different locations in the cab, five on the headrests, two on the B pillars and one at the head position of the sleeping
Wang PhD, Jian, Ling, Zihong, Zhang, Zhe, Cai, DeHua, lv, Xiao, Zhang, Ming, Gao, GuoRan
Identification and Evaluation of Passthroughs That Affect the Acoustic Performance of a Dash System2025-01-012105/05/2023
This paper discusses a systematic process that was developed to evaluate the acoustic performance of a production electric vehicle dash system. The production dash panel was tested under different configurations to understand the importance of passthroughs in the acoustics of the dash system. Results show that often the performance of the passthroughs strongly affects the overall performance of the dash system and this may become the limiting factor to increase the system STL. The dash with passthroughs was then extensively tested to understand the acoustic strength of different passthroughs and to understand how these passthroughs affect the overall performance of the dash system. Subsequently a test procedure based on flat panel tests was developed so the OEM can develop target values and the suppliers can provide test results of their passthroughs that are meaningful and useful to the OEM to help build an acoustically competitive vehicle.
Saha, Pranab, Baack, Gregory, Geissler, Christian, Kaluvakota, Srikanth, Pilz, Fernando
Excavator exterior noise contribution analysis using angle-based operational acoustic load synthesis.2025-01-006205/05/2023
Since earth moving machines (EMM) are subject to exterior noise (EN) regulations, OEMs need to develop mitigation solutions from an early design stage. It is challenging to predict solution effectiveness at early design stage. Excavators are distinct compared to other EMM as their upper frame rotate while keeping lower frame fixed. ISO 6395(2) or EC/2000/14(1) require EMMs to follow specific operating maneuvers where noise sources change their position, directivity, and speed along the operating cycle. These conditions pose challenges in performing noise contribution analysis as a function of angular position and operating condition. Authors successfully demonstrated Acoustic source quantification and contribution analysis for linearly moving EMMs. However, excavator pose data processing challenges due to angular motion. This work demonstrates the use of frequency domain ASQ for operational acoustic source quantification and use of frequency domain virtual prototype sub structuring
Vesikar, Prasad Balkrishna, Haynes, Timothy, Aquino Arriaga, Adrian Antonio, Drabison II, John, Chaduvula, Prasanna
Cairene Car-Culture: How are Automobility and Social Behavior Linked to The Development of The Soundscape and Urban Fabric of Cairo.2025-01-006905/05/2023
Cairo’s soundscape has witnessed changes due to the ongoing urban structure developments that accommodate the number of vehicles passing through the city. The soundscape produced by this growing automobility is affected not only by vehicles but also by their owners' behavior. Cairenes use their cars as a communication tool and an extension of private space. By viewing the vehicle as a component of the soundscape as well as a space that filters it, this study examines the synergy between social behavior, automobility, urban structure, and their interdependent relationship on the soundscape of Cairo. The study responds to literature elaborating on acoustic ecology, car culture, urban structure, and social behavior. The methodology applied in this study follows practice-based phenomenological research while documenting and reflecting on car cultural practices in Cairo from an aural perspective. Grounded theory contextualizes the analysis of archived audio and video material, semi
Abd El Naby, Abla Mohamed
Monitoring Brake Wear with Acoustics2021-01-105308/31/2021
A new approach for detecting problems with vehicle brakes by analyzing sounds emitted during braking events is proposed. Vehicle brakes emit acoustic energy as part of the braking process; the spectra of these sounds are highly dependent on the mechanical condition of the brake and can be used to detect problems. Acoustic theory indicates that as brake linings wear thinner the resonant frequency of the shoe or pad increases, potentially enabling the monitoring of lining wear through passive acoustic sensors. To test this approach, passive acoustic sensors were placed roadside at the exit of a transit bus facility for 9 months. The sensors collected almost 10,000 recordings of a fleet of 160 vehicles braking over a variety of conditions. Spectra of vehicles that had brake work performed during this period were analyzed to compare differences between new and worn friction linings. It was found that the spectra changes as friction linings wear, in concurrence with acoustic theory, where
Hearing, Brian, Grove, Kevin, Alden, Andrew
Study of the Effects of Active Noise Cancellation on Music Playback2021-01-101608/31/2021
Technology for automotive active noise cancellation (ANC) such as HARMAN’s Engine Order Cancellation (EOC) system help reduce in-cabin noise levels using a set of error microphones and the vehicle’s built-in audio system to generate anti-noise signals. A major benefit of these systems is that significant reduction in unwanted noise levels in the 20 - 400 Hz range can be achieved without the addition of extra noise control material. However, in the instances where the frequencies of anti-noise signals and music signals overlap, a degradation in the overall music reproduction quality is possible. In this paper, we study the effects of EOC on music playback by applying signal processing and statistical methods to objectively measure degradation in audio content when EOC is active. This study is carried out using production EOC software in a simulation environment. The simulation models the cabin acoustic response from measured vehicles and uses recordings of vehicle noise and music as
Basu, Sattwik, Tackett, Jeffrey, Trumpy, David, Walt, Adam, Adari, Santosh
Multiphysics Simulation of Electric Motor NVH Performance with Eccentricity2021-01-107708/31/2021
With the emphasis of electrification in automotive industry, tremendous efforts are made to develop electric motors with high efficiency and power density, and reduce noise, vibration and harshness (NVH). A multiphysics simulation workflow is used to predict the eccentricity-induced noise for GM’s Bolt EV motor. Both static and dynamic eccentricities are investigated along with axial tilt. Analysis results show that these eccentricities play a critical role in the NVH behavior of the motor assembly. Transient electromagnetic (EM) analysis is performed first by extruding 2D stator and rotor sections to form 3D EM models. Sector model is duplicated to form full 360-degree model. Stator is split into three rotated sections to characterize stator skew, and the skew between two sections of rotor and magnets are also modelled. Sinusoidal current is applied and lumped-sum forces on each stator tooth are computed. Next, full 3D structural model is constructed, and EM forces are applied as
Zhang, Henry, Jaura, Ankur, Kumar, Dinesh, Sambharam, Tushar, Zhang, Zheming, He, Song, Zhang, Peng, GSJ, Gautam
Pass by Noise Analysis Method Extended for Mitigation Solution Development on Earth Moving Machinery2021-01-107108/31/2021
Pass-by/exterior noise of earth moving machines (EMM) and forestry machines is becoming a focus at early product development stages. ISO 6395 (2) or EC/2000/14 (1) standards defines exterior noise test procedure for EMM. However, these standards do not provide insights for diagnosing any noise issues which may arise. The analysis challenges are posed by the moving machine and acoustic sources with respect to the stationary hemisphere target microphone on the ground and changing operating condition of sources as function of time. There is need to develop a seamless methodology to identify acoustic sources, quantify respective source strengths and rank partial contributions from each source to the total target microphone response in order to overcome the aforementioned challenges. This paper demonstrates use of time and frequency domain Acoustic Source Quantification (ASQ) combined with time domain overall sound pressure level computation to mimic operational test conditions which
Vesikar, Prasad Balkrishna, Drabison II, John, Rawal, Abhay, Chaduvula, Prasanna, Wood, Cary, Sullivan, Joseph
Synergy of Methods in Structural Dynamics: TPA and Modal Analysis2021-01-109008/31/2021
Since NVH is always a property of the whole system, one must have a deep understanding of the dependencies and all the components that interact. The well known in-situ Transfer Path Analysis (TPA) provides methods to separate different components of an acoustical system such as source and receiver. The source including excitation and structural dynamics of the exciting subsystem can be described independently of the structural dynamics of the receiving structure by means of the in-situ blocked forces. The Experimental Modal Analysis (EMA) is a common method as well and aims to identify the structural dynamics of a structure. This paper addresses the combination of both methods using the example of an e-drive of an electric car, which has been analyzed on a test rig. The combination of modal analysis and TPA yields a better understanding of the system and its dependencies. The correlation of the results of both methods can be used to gain important insights regarding the source
Wegerhoff, Matthias, Sottek, Roland, Brücher, Haiko, Kamper, Tim
Root-Cause Analysis, and Improvement of a Port Fuel Injected V6 Vehicle to Achieve Best-In-Class Sound Quality2021-01-104108/31/2021
This paper will communicate an in-depth investigation uncovering contributing factors defining the desired and undesired acoustic signature of a V6 Vehicle. A transfer path analysis tool is exercised to rank improvement opportunities. These results are used to drive design improvements with the goal of achieving best-in-class sound quality when executed as a system. A cohesive powertrain-vehicle-level acoustic improvement package is executed, improving air induction, intake manifold, both structure and air-core, exhaust-radiated and under-hood-acoustic encapsulation. The acoustic package was validated by jury testing to provide significant refinement enhancement improving predicted 3rd party scores.
Brosseau, Justin, Yuan, Wei, Singh, Vinod, Orzechowski, Jeff
Subjective and Objective Seat Feature Acoustic and Vibration Response2021-01-107508/31/2021
Compressors, fans, and valves in seats used for occupant height adjust, lumbar, heating, and cooling can be objectionable if felt or heard. An approach to measure subjectively and objectively both vibration and noise experienced by a seated occupant will be described along with results, ranking, statistical significance, correlation, and suggestions for noise control. The objective portion included acoustic measurements through a binaural headset worn by each occupant and vibration measurements were recorded using a seat pad accelerometer disc at the buttocks and a source accelerometer. A subjective questionnaire with Likert, Borg, Magnitude Estimation, Semantical Differences, and Ranking based questions was obtained from 9 subjects. The transfer path the vibration energy takes to reach the receiver, vibration or acoustic, will be explored with transfer function measurements and a discussion of potential mitigation techniques: source mounting, encapsulation, and other design
Haylett, Jim, Romagosa, Francesc, Nelson, Erik
A Novel Dissipative Acoustic Material2021-01-112808/31/2021
Due to modern trends in the automotive industry, such as vehicle electrification, light-weighting, reduced NVH (Noise, Vibration and Harshness) packaging space, etc., it is desirable to have a low profile and light-weight acoustic material with multi-functionality. If one single layer of a thin acoustic material can provide comparable absorption and transmission loss to a multilayer treatment, it will benefit the industry by saving weight, packaging space and system cost. Acoustic absorption and sound transmission loss performance of a new dissipative material at reduced weight and thickness is introduced in this paper. The acoustic performance of the material was evaluated by using random incidence absorption and transmission loss as well as in-vehicle experiment. Further potential applications for this material have been identified using the Statistical Energy Analysis (SEA) method with panel leakage considered.
Yoo, Taewook, Gerdes, Ronald, Lee, Seungkyu, Shi, Tongyang
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