Skip to Main content Skip to Navigation
Theses

Audition et démasquage binaural chez l'homme

Abstract : Background: Binaural unmasking is an essential process for understanding in noisy environments. This mechanism would involve the comparison of time and frequency cues throughout the hearing nerve pathways. However, there is no real consensus evoking a treatment of a binaural masking release at a subcortical and/or a cortical level. The purpose of this study is to investigate the time and frequency cues of the binaural unmasking through a perceptual study, and then through an electroencephalographic study (EEG).Materials and Methods: Normal hearing people were evaluated with a perceptive study to estimate the importance of the binaural unmasking according to 1) the frequency width of the contralateral noise (1 octave, 3 octaves or broadband), 2) the temporal coherence of bilateral noises (correlation equal to 0 or 1) and 3) the frequency of the target stimuli (0.5, 1, 2 and 4 kHz). Binaural unmasking was then evaluated with EEG by studying 1) early latencies (<10 ms, PEA-P), 2) late latencies (<50 ms, PEA-T) and 3), the mismatch wave (PEA- MMN). For these three EEG studies, the influence of the temporal coherence of bilateral noise was investigated.Results: The study shows a growing perceptive binaural unmasking when the frequency width of the contralateral noise increases. The addition of an uncorrelated contralateral noise (correlation = 0) results in a 1.28 dB detection enhancement, regardless of the frequency of the target stimuli (antimasking), while adding a contralateral correlated noise (correlation = 1) refers to a detection enhancement when the frequency of the target stimuli decreases (unmasking): 0.97 dB at 4 kHz and 9.25 dB at 0.5 kHz. The latencies of waves III and V are shortened when a contralateral correlated or uncorrelated noise is added (≈0,1 ms) in the PEA-P. The amplitudes of P1, N1 waves and P1N1 and N1P2 complex increase when contralateral correlated or uncorrelated noise is added in PEA-T. Finally, the amplitude of the MMN is higher when a contralateral correlated noise is added (versus an uncorrelated one).Conclusion: The perceptual study shows the significance of spectral cues (antimasking) and temporal cues (unmasking), to improve the perception of an initially masked signal. The EEG study suggests a subcortical treatment which is only influenced by spectral cues (antimasking) and a cortical processing, influenced by temporal cues (unmasking).
Complete list of metadatas

Cited literature [238 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-01508857
Contributor : Abes Star :  Contact
Submitted on : Friday, April 14, 2017 - 7:12:06 PM
Last modification on : Tuesday, May 28, 2019 - 5:00:03 PM
Document(s) archivé(s) le : Saturday, July 15, 2017 - 4:10:49 PM

File

2016_LORENZI_archivage.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01508857, version 1

Collections

Citation

Antoine Lorenzi. Audition et démasquage binaural chez l'homme. Médecine humaine et pathologie. Université Montpellier, 2016. Français. ⟨NNT : 2016MONTT003⟩. ⟨tel-01508857⟩

Share

Metrics

Record views

584

Files downloads

2241