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Musical period as a factor in exposing orchestra musicians to loud sounds

Żera Jan, Goluch Paulina, Pietrzak Agnieszka Paula

Vibrations in Physical Systems

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2022

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Vol. 33, nr 3

art. no. 2022318

EN

Numerous studies on noise exposure and hearing loss risk of musicians playing in symphonic or chamber ensembles have been published in the literature. Typically, such studies present data averaged over a specific measurement time during which various repertoire is played, usually not thoroughly analyzed. This often creates concerns that the selection of musical pieces for the measurement may be an important factor determining the sound exposure. Our study was undertaken to examine how the musical repertoire from the classical, neo-romantic and 20th century periods differs in the exposure level (LAeq) measured near the ears of musicians who play various instruments. The results show that the difference caused by the selection of the repertoire may range from 2 to 6 dB(A), depending on the instrument. In the case of some instruments such a difference may cause a significant change in the physiological load imposed on the musicians’ auditory system.

2

Application of an ambisonic microphone for the measurements of room acoustic parameters

Jasiński Maciej, Żera Jan

Vibrations in Physical Systems

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2022

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Vol. 33, nr 3

art. no. 2022312

EN

The most commonly used measurement technique in room acoustics employs a single omnidirectional microphone for recording the room impulse response and further derivation of such acoustical parameters as T30, EDT, C50 or C80. Instead, ambisonic technology makes it possible to measure a spatial room impulse response. Ambisonics decomposes the signal from the spherical microphone array into spherical harmonics to shape the directivity. Ambisonics lets to go beyond basic acoustical parameters and allows to determine spatial features of a sound field at the measurement point. This study presents the comparison of fundamental acoustic parameters measured in the recording studio by an actual omnidirectional microphone and virtual omnidirectional microphones derieved from ambisonic microphones of the first and third order. The results show the usefulness of ambisonic technology in terms of assessing basic room parameters.

3

Estimation of Asymmetry in Head Related Transfer Functions

Jasiński Maciej, Żera Jan

International Journal of Electronics and Telecommunications

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2022

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Vol. 68, No. 2

193--200

EN

The individual Head-Related Transfer Functions (HRTFs) typically show large left-right ear differences. This work evaluates HRTF left-right differences by means of the rms measure called the Root Mean Square Difference (RMSD). The RMSD was calculated for HRTFs measured with the participation of a group of 15 subjects in our laboratory, for the HRTFs taken from the LISTEN database and for the acoustic manikin. The results showed that the RMSD varies in relation to the frequency and as expected is small for more symmetrical HRTFs at low frequencies (0.3÷1 kHz). For higher frequency bands (1÷5 kHz and above 5 kHz), the left-right differences are higher as an effect of the complex filtering caused by anatomical shape of the head and the pinnae. Results obtained for the subjects and for data taken from the LISTEN database were similar, whereas different for the acoustic manikin. This means that measurements with the use of the manikin cannot be considered as perfect average representation of the results obtained or people. The method and results of this study may be useful in assessing the symmetry of the HRTFs, and further analysis and improvement of how to considered the HRTFs individualization and personalization algorithms.

4

Timbre Solfege and auditory profile analysis

Żera Jan

Vibrations in Physical Systems

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2019

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Vol. 30, nr 1

art. no. 2019122

EN

A course in auditory evaluation of sound, called Timbre Solfege, was developed by a team of researchers headed by Professor Andrzej Rakowski, at the Music Acoustics Laboratory, Chopin University of Music. A large part of the course, taught at the Department of Sound Engineering, has been focused on the detection and identification of timbre changes produced by formants and by other kind of sound spectrum modifications. Detecting formants in sound recordings is an auditory task that has much in common with auditory profile analysis, an area of research initiated and developed in psychoacoustics by Professor David M. Green, exploring the fundamentals of detection of changes in the sound spectrum envelope shape, independently of the differences in loudness between the sounds. The purpose of this study is an attempt to relate the results of the Timbre Solfege sound evaluation drills to the theory of the auditory profile analysis.