Measures and perceptual correlates of signal envelope changes induced by hearing aid compression
Abstract
The motivation for this investigation was that envelope cues are important for understanding speech, whereas the compression system in a hearing aid will change the speech signal’s envelope. Especially when the compression system is acting on a mix of speech and uctuating noise, the changes of the speech signal envelope become complex. Three measures for quantifying different aspects of the induced envelope changes have been investigated: Across Source Modulation Correlation (ASMC), Envelope Difference Index (EDI) and the change of the long-term Signal to Noise Ratio at the hearing aid output (∆SNR). These three measures and combinations of these were compared against the outcome of speech intelligibility tests performed on 14 normal-hearing listeners using vocoded speech and noises. The noises were all uctuating with speech-like temporal properties. The speech material was based on the Dantale II test corpus and the masking noises on either ICRA two-talker modulated noise or a Danish audio book. The ndings indicate how predictive the different measures are for speech intelligibility, and suggest that the effects of hearing aid compression on speech intelligibility are complex and cannot be covered by a single aspect of envelope changes.
References
Fortune, T. W., Woodruff, B. D., and Preves, D. A. (1994). “A new technique for quantifying temporal envelope contrasts,” Ear Hear 15, 93-99.
Naylor, G., and Burmand Johannesson, R. (2009). “Long-Term Signal-to-Noise Ratio (SNR) at the Input and Output of Amplitude Compression Systems,” J Am Acad Audiol 20, 161-171.
Naylor, G., Rønne, F. M., and Burmand Johannesson, R. (2008). “Perceptual correlates of the long-term SNR change caused by fast-acting compression” ICHON 2008 poster presentation.
Hagerman, B., and Olofsson, Å. (2004). “A Method to Measure the Effect of Noise Reduction Algorithms Using Simultaneous Speech and Noise,” Acta Acustica 90, 356–361.
Hopkins, K., and Moore, B. C. J. (2007). “Moderate cochlear hearing loss leads to a reduced ability to use temporal ne structure information,” J. Acoust. Soc. Am. 122, 1055–1068.
Wagener, K., Lignel Josvassen, J. and Ardenkjær, R. (2003). “Design, optimization and evaluation of a Danish sentence test in noise,” International Journal of Audiology 42, 10-17.
Dreschler, W. A., Verschuure, H., Ludvigsen, C., and Westermann, S. (2001). “ICRA noises: arti cial noise signals with speech-like spectral and temporal properties for hearing instrument assessment,” Audiology 40, 148-157.
Additional Files
Published
How to Cite
Issue
Section
License
Authors who publish with this journal agree to the following terms:
a. Authors retain copyright* and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
b. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
c. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
*From the 2017 issue onward. The Danavox Jubilee Foundation owns the copyright of all articles published in the 1969-2015 issues. However, authors are still allowed to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
