Journal article
Stimulus frequency otoacoustic emissions extracted by pharmacologic blocking of outer hair cells without sound suppression or subtractive scaling
AIP conference proceedings, Vol.3062(1), 030005
NONLINEARITY AND HEARING: ADVANCES IN THEORY AND EXPERIMENT: Proceedings of the 14th International Mechanics of Hearing Workshop
02/27/2024
DOI: 10.1063/5.0190184
Abstract
Stimulus-frequency otoacoustic emissions (SFOAEs) are important non-invasive probes of cochlear function. The SFOAE is usually separated from the probe sound by measuring a response that contains both the probe sound and the SFOAE, and then subtracting a separate measurement of the probe sound alone. The probe-alone measurement is obtained using (1) a high-level, near-frequency “suppressor” sound assumed to suppress the SFOAE, or (2) the probe sound at a high level where the SFOAE is small compared to the probe (i.e., is compressed) and is presumed to be negligible after the high-level measurement is scaled down to the probe level. To the extent that the high-level sound has a negligible SFOAE, the complete SFOAE should theoretically be extracted by the subtraction. However, a potential complication is that the high-level sounds may produce unintended SFOAE components, particularly from basal cochlear regions. Here we use a novel technique to address the extent to which the high-level suppressor sound and subtraction extracts the full SFOAE without producing unintended additional energy at the probe frequency. Measurements were made with a standard high-level suppressor-tone extraction paradigm, and the resulting SFOAEs were compared to SFOAEs obtained using a pharmacologic SFOAE reduction that does not require a high-level sound. We made SFOAE measurements in guinea pigs while sequentially abolishing outer-hair-cell (OHC) function and SFOAE amplification by slowly perfusing salicylate or KCl solutions into the cochlear apex. The solution fronts were driven uniformly along the cochlear length toward the cochlear aqueduct in the cochlear base. This approach removes cochlear amplification at a given cochlear place without simultaneously affecting amplification or responses that originate basal to this place. At the end of the perfusion when OHC function and SFOAE production were pharmacologically blocked throughout the entire cochlear length, the probe sound alone (i.e., with no accompanying SFOAE) could be measured directly without the need for a high-level suppressor. SFOAEs were calculated by subtracting probe-only ear canal measurements made after the perfusion from measurements made before and during the perfusion. SFOAEs extracted using the apical perfusion technique, i.e., pharmacologic blocking, differed little from the SFOAEs extracted using a near-frequency high-level suppressor sound but were, on average, a few dB higher in amplitude. This suggests that the near-frequency high-level tone suppressed most, but not all, of the SFOAE.
Details
- Title: Subtitle
- Stimulus frequency otoacoustic emissions extracted by pharmacologic blocking of outer hair cells without sound suppression or subtractive scaling
- Creators
- Shawn S. Goodman - University of IowaDaniel Tay - University of IowaJeffery T. Lichtenhan - Washington University in St. LouisJohn J. Guinan - Massachusetts Eye and Ear Infirmary
- Contributors
- Wei Dong (Editor) - Loma Linda UniversityBastian Epp (Editor) - Technical University of Denmark
- Resource Type
- Journal article
- Publication Details
- AIP conference proceedings, Vol.3062(1), 030005
- Conference
- NONLINEARITY AND HEARING: ADVANCES IN THEORY AND EXPERIMENT: Proceedings of the 14th International Mechanics of Hearing Workshop
- DOI
- 10.1063/5.0190184
- ISSN
- 0094-243X
- eISSN
- 1551-7616
- Number of pages
- 8
- Date published
- 02/27/2024
- Academic Unit
- Communication Sciences and Disorders
- Record Identifier
- 9984563459402771
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