Output compensation of auditory brainstem responses in dolphins and sea lions.
J Acoust Soc Am
; 151(5): 3070, 2022 05.
Article
in En
| MEDLINE
| ID: mdl-35649923
ABSTRACT
Cochlear dispersion causes increasing delays between neural responses from high-frequency regions in the cochlear base and lower-frequency regions toward the apex. For broadband stimuli, this can lead to neural responses that are out-of-phase, decreasing the amplitude of farfield neural response measurements. In the present study, cochlear traveling-wave speed and effects of dispersion on farfield auditory brainstem responses (ABRs) were investigated by first deriving narrowband ABRs in bottlenose dolphins and California sea lions using the high-pass subtractive masking technique. Derived-band ABRs were then temporally aligned and summed to obtain the "stacked ABR" as a means of compensating for the effects of cochlear dispersion. For derived-band responses between 8 and 32 kHz, cochlear traveling-wave speeds were similar for sea lions and dolphins [â¼2-8 octaves (oct)/ms for dolphins; â¼3.5-11 oct/ms for sea lions]; above 32 kHz, traveling-wave speed for dolphins increased up to â¼30 oct/ms. Stacked ABRs were larger than unmasked, broadband ABRs in both species. The amplitude enhancement was smaller in dolphins than in sea lions, and enhancement in both species appears to be less than reported in humans. Results suggest that compensating for cochlear dispersion will provide greater benefit for ABR measurements in species with better low-frequency hearing.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sea Lions
/
Bottle-Nosed Dolphin
Limits:
Animals
Language:
En
Journal:
J Acoust Soc Am
Year:
2022
Document type:
Article
Affiliation country:
United States
Publication country:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA