Journal-Online

Home / Publications / Journal-Online

Journal of the Audio Engineering Society

>> Institutional Subscribers: View Your List of Purchased Issues

2022 April - Volume 70 Number 4

Download Entire Issue (19.34 MB)

*Only AES members and Institutional Journal Subscribers can download.

Papers

Automatic Quality Assessment of Digitized and Restored Sound Archives

Authors: Ragano, Alessandro; Benetos, Emmanouil; Hines, Andrew

OPEN ACCESS

Archiving digital audio is conducted to preserve and make records accessible. However techniques for assessing the quality of experience (QoE) of sound archives are usually neglected. This paper presents a framework to assess the QoE of sound archives in an automatic fashion. The QoE influence factors, stakeholders, and audio archive degradations are described, and the above concepts are explored through a case study on the NASA Apollo audio archive. Each component of the framework is described in the audio archive life cycle based on digitization, restoration, and consumption. Insights and real-world examples are provided on why digitized and restored audio archives benefit from QoE assessment techniques similar to other multimedia applications, such as video calling and streaming services. The reasons why stakeholders, such as archivists, broadcasters, or public listeners, would benefit from the proposed framework are also provided.

Download: PDF (HIGH Res) (10.33 MB)

Download: PDF (LOW Res) (764.09 KB)

On the Differences in Preferred Headphone Response for Spatial and Stereo Content

Authors: Engel, Isaac; Alon, David L.; Scheumann, Kevin; Crukley, Jeff; Mehra, Ravish

OPEN ACCESS

When reproducing spatial audio over headphones, ensuring that these have a flat frequency response is important to produce an accurate rendering. However, previous studies suggest that, when reproducing nonspatial content such as stereo music, the headphone response should resemble that of a loudspeaker system in a listening room (e.g., the so-called Harman target). It is not yet clear whether a pair of headphones calibrated in such way would be preferred by listeners for spatial audio reproduction too. This study investigates how listeners' preference regarding headphone frequency response differs in the cases of stereo and spatial audio content reproduction, rendered using individual binaural room impulse responses. Three listening tests that evaluate seven different target headphone responses, two headphones, and two reproduction bandwidths are presented with over 20 listeners per test. Results suggest that a flat headphone response is preferred when listening to spatial audio content, whereas the Harman target was preferred for stereo content. This effect was found to be stronger when user-specific equalization was used and was not significantly affected by the choice of headphone or reproduction bandwidth.

Download: PDF (HIGH Res) (7.09 MB)

Download: PDF (LOW Res) (3.07 MB)

A Design Method for Low-Order Accurate Parallel Graphic Equalizers

Authors: Li, Ya; Yang, Junjie; Feng, Qi; Wing-Kuen Ling, Bingo

Automotive audio graphic equalizers are limited by the cost and hardware resources, so it is hoped that the number of equalization filters should be as few as possible while ensuring the correction effect. To solve this problem, a design method for low-order accurate parallel graphic equalizers is proposed and applied to automotive loudspeakers, which can reduce the number of equalization filters without losing correction accuracy. First the identification of the loudspeaker frequency response range and adaptive calculation of filter target gain settings are proposed for automotive application. Then the filter target gain settings are dynamically selected, and the filter bandwidth is automatically adjusted, which can reduce the number of equalization filters and correct the car loudspeaker sound field with high precision. The experimental results show that under the background of automotive application, the average corrected spectral flatnessmeasure of the proposed method is comparable to the state-of-the-art methods, and the average number of equalization filters is reduced by about 25%.

Download: PDF (HIGH Res) (3.82 MB)

Download: PDF (LOW Res) (754.66 KB)

Design and Evaluation of Electric Vehicle Sound Using Granular Synthesis

Authors: Lazaro, May Jorella; Kim, Sungho; Choi, Minsik; Kim, Kichang; Park, Dongchul; Moon, Soyoun; Yun, Myung Hwan

Electric vehicles (EVs) generally do not have the natural engine sound; thus, sound design for such vehicles is more crucial. This study focuses on proposing an EV interior sound design through utilizing the granular synthesis method. Moreover, it aims to investigate the effect of each granular synthesis parameter on the drivers' affective experience. In the model proposed, four granular synthesis parameters (sample source, grain duration, grain envelope, and revolution per minute [RPM] range) with three levels each were selected for synthesis. By combining different values of each sound parameter in an orthogonal array, 27 EV sound samples were generated. A jury test was conducted with 32 participants (20 male, 12 female), which evaluated each sound sample based on three EV-related affective adjectives ("refined," "sporty," and "futuristic") and ratings of overall satisfaction. The results showed that each granular synthesis parameter has a different impact on the perception of EV-related affect and satisfaction. Moreover, it also found that combining different values of each parameter may result in inducing a specific emotion or experience. The EV sound design methodology proposed in this study can contribute to the development of future EV sound to increase its effectiveness in improving the drivers' auditory experience.

Download: PDF (HIGH Res) (4.05 MB)

Download: PDF (LOW Res) (624.18 KB)

Managing the Live-Sound Audio Engineer`s Most Essential Critical Listening Tool

Authors: Compton, Stephen

OPEN ACCESS

Critical listening is the live-sound audio engineer's most essential tool for informed sonic assessment. In producing a cohesive mix that fulfills an event's aims, audio engineers affect the experience and well-being of all live-sound participants. This study compares the results from a 2020 international audio engineer survey with published research. The findings demonstrate that although in theory, engineers recognize their hearing as being their most essential critical listening tool, in practice, many have not foundways to manage their hearing and optimize their assessment ability effectively. Many engineers with impeded or impaired hearing continue to mix, believing that any negative impact on participants is minimal or nonexistent. The livesound experience and participant health and well-being are improved by promoting and acting on appropriate hearing management practices.

Download: PDF (HIGH Res) (2.55 MB)

Download: PDF (LOW Res) (958.83 KB)

Engineering reports

Variable Resonator Cap for User-Definable Microphone High Frequency Response

Authors: Grigg, Benjamin

Resonator caps have been used for several decades to refine the high frequency response of microphones. These caps create a resonant cavity in front of the diaphragm to extend and shape the high frequency response. This work studies the experimental use of a variable-geometry resonator cap. This cap allows the user to select a desired high frequency response in real time, using only acoustic methods. Data collected in an anechoic chamber shows clear changes to microphone on-axis high frequency response with just small changes to the geometry of the resonator cap. This concept could be applied to allow user-adjustable high frequency response in a microphone, or it could be used as a lab tool to help acousticians quickly find the desired resonator dimensions.

Download: PDF (HIGH Res) (2.57 MB)

Download: PDF (LOW Res) (322.33 KB)