Effect of ear canal occlusion on loudness perception
Résumé
The common practice to estimate the noise exposure of workers wearing hearing protection devices is to measure the ambient noise at the worker’s position and then subtract the attenuation provided by the hearing protector. In the case of communication equipment, such noise measurement needs to be realized directly at the wearer’s ear and then converted into equivalent free field data using the transfer function of the open ear. None of these methods account for any change of sensitivity caused by the presence of the in-ear or over-the-ear device. Indeed, it is generally assumed that noise sensitivity should remain constant for a given frequency and sound pressure level at the eardrum, whatever the listening conditions.
The present study investigates the potential effect of ear canal occlusion on loudness perception. An experiment was made on human participants to compare the equal loudness sound pressure levels obtained in an open vs. occluded ear. Each subject was asked to perform loudness balancing tests at several frequencies in the open and occluded ear. Headphones were used as a source on both sides while one ear was equipped with an earplug. Both ears were equipped with small microphones for measuring the in-ear sound pressure levels.
This paper details the experimental design and results obtained on a pilot group. A clear difference appears for frequencies ranging from 125 Hz to 1 kHz, where the equal loudness sound pressure levels were measured on average to be 4 to 8 dB higher in the occluded ear. These findings, which raise questions as regards the determination of noise exposure received by workers wearing earplugs, also are a key point to consider for new emerging in-ear dosimetry applications.
Fichiers supplémentaires
Publié-e
Comment citer
Numéro
Rubrique
Licence
Author Licensing Addendum
This Licensing Addendum ("Addendum") is entered into between the undersigned Author(s) and Canadian Acoustics journal published by the Canadian Acoustical Association (hereinafter referred to as the "Publisher"). The Author(s) and the Publisher agree as follows:
-
Retained Rights: The Author(s) retain(s) the following rights:
- The right to reproduce, distribute, and publicly display the Work on the Author's personal website or the website of the Author's institution.
- The right to use the Work in the Author's teaching activities and presentations.
- The right to include the Work in a compilation for the Author's personal use, not for sale.
-
Grant of License: The Author(s) grant(s) to the Publisher a worldwide exclusive license to publish, reproduce, distribute, and display the Work in Canadian Acoustics and any other formats and media deemed appropriate by the Publisher.
-
Attribution: The Publisher agrees to include proper attribution to the Author(s) in all publications and reproductions of the Work.
-
No Conflict: This Addendum is intended to be in harmony with, and not in conflict with, the terms and conditions of the original agreement entered into between the Author(s) and the Publisher.
-
Copyright Clause: Copyright on articles is held by the Author(s). The corresponding Author has the right to grant on behalf of all Authors and does grant on behalf of all Authors, a worldwide exclusive license to the Publisher and its licensees in perpetuity, in all forms, formats, and media (whether known now or created in the future), including but not limited to the rights to publish, reproduce, distribute, display, store, translate, create adaptations, reprints, include within collections, and create summaries, extracts, and/or abstracts of the Contribution.
