Effects of pure tone frequency position in inverter noise on perceived unpleasantness

Takuma Kasori･Masahiko Kondo･Masao Yamaguchi･Takeshi Toi (Chuo university)

The sound generated by inverter is composed of multiple pure tone components. This study examined the relationship between masking effects of these components and perceived unpleasantness, focusing on critical bands. It was found that within critical bands, increased dissonance leads to higher levels of unpleasantness. These findings provide practical guidelines for sound quality design of inverters, indicating which frequency position should be avoided to minimize unpleasant auditory perception.

Sound Quality Evaluation by SD Method for Passenger HVAC Noise (2nd Report)

Hideo Takao (Sekiso Corportaion)

In the previous report, we conducted sound quality evaluations of passenger car HVAC noise using the SD method and derived regression equations for subjective evaluations based on loudness and sharpness within the“unpleasant ⇔ pleasant” adjective pairs. We also reported on their practical applicability. In this report, we similarly investigated the relationship between subjective evaluations SD method using other adjective pairs and psychoacoustic metrics, and report on the new findings obtained.

A Proposal of a Musical Score-Based Sound Design Method for Electric Vehicles

Norio Kubo (EV Soundscape)

The quietness of electric vehicles (EVs) has created new demands for both exterior and interior sound design. This study proposes a novel acoustic design method that interprets EV sounds as string-instrument-like phenomena and structures their temporal and frequency characteristics using a musical score-based approach, aiming to achieve a balance between brand expression and safety. First, the contradictory requirements of warning functionality and brand representation inherent in AVAS are examined. Next, we present a method for reconstructing physical and psychoacoustic parameters along a musical time axis. Furthermore, we introduce a design process that bridges AI-based sound quality evaluation (AI-SQ engineering) and creative sound design. For interior sound, we demonstrate how a musical score-based framework can be applied to Active Sound Design (ASD) by analyzing the effectiveness of structured elements such as sound initiation (expectation), development, and transition. For exterior sound, we propose a score-based structural model suitable for AVAS, using the concept sound “Energy” as a case study. These approaches together present a new framework for EV sound design that integrates both functional requirements and emotional value.

Analysis of the Optimal Time History Window for an Engine Noise Perception Prediction Model Using Vehicle Parameters under Different External Stimulus Conditions

Shinichi Suganuma (Chuo University, Graduate School of Science and Engineering)･Shimpei Nagae (Nissan Motor)･Takeshi Toi (Chuo University)

In a previous study using on-road driving data, the highest estimation accuracy was obtained when a 5.5-second time history of engine speed was added to an engine noise perception prediction model that used vehicle parameters as explanatory variables. To clarify the factors that determine this optimal time history window, the present study used a driving simulator in which driving-related external stimulus conditions were varied, including the presence or absence of driving operations and visual information. The influence of these external conditions on the time history window required to achieve maximum prediction accuracy was examined.

Objective Evaluation Method for Interior Sound Quality in Electric Vehicles (First Report)
-Sound Quality Evaluation Method for In-Cabin Electric Powertrain Noise-

Kenji Torii･Kenya Fujii (Honda Motor)

To quantitatively evaluate the sound quality of in-cabin powertrain noise in electric vehicles, a subjective evaluation experiment was conducted with 14 experts using Scheffé's paired comparison method. By analyzing the relationship between the subjective results and psychoacoustic analysis results, key sound quality metrics for electric powertrain noise were identified.

Prediction Method for In-Cabin Powertrain Noise in Electric Vehicles Using Powertrain-Bench Test Data

Kenji Torii･Shion Mise (Honda Motor)･Philipp Sellerbeck (Head Acoustics)･Kenta Tanabe (HEAD acoustics Japan Co.)

The authors are developing a new NVH design process that utilizes an NVH driving simulator to enhance the interior sound quality of electric vehicles from the early design stage, prior to prototype production. In this study, as part of that effort, three estimation methods for predicting in-cabin powertrain noise were developed using powertrain bench test data based on component-based TPA. Their applicability to the proposed development process was examined and confirmed.

A Study on the Detailed Classification of Vehicle Fuel Pump Noise and Improvement Method for Each Noise Generated

JUNGHOON PARK･KEUNSOO KIM･SEUNGHWAN PARK･DONGHYUN KIM (Hyundai Motor)

Noise and vibration have a great influence on the emotional performance of a vehicle. Noise is inevitably generated in the fuel system when the engine of an internal combustion engine vehicle is driven. With the development of sound insulation technology of the vehicle body, the noise from outside of the vehicle has been greatly improved. Therefore, the noise of the fuel system connected to the vehicle body has been highlighted. Elements such as the pump and jet pump of the fuel system as a noise source, and components such as the vehicle body and the fuel tank as noise transfer paths were analyzed. Through this, each noise was classified in detail to find the cause of the occurrence and improvement plan