Publication
Title
Do high sound pressure levels of crowing in roosters necessitate passive mechanisms for protection against self-vocalization?
Author
Abstract
High sound pressure levels (> 120 dB) cause damage or death of the hair cells of the inner ear, hence causing hearing loss. Vocalization differences are present between hens and roosters. Crowing in roosters is reported to produce sound pressure levels of 100 dB measured at a distance of 1 m. In this study we measured the sound pressure levels that exist at the entrance of the outer ear canal. We hypothesize that roosters may benefit from a passive protective mechanism while hens do not require such a mechanism. Audio recordings at the level of the entrance of the outer ear canal of crowing roosters, made in this study, indeed show that a protective mechanism is needed as sound pressure levels can reach amplitudes of 142.3 dB. Audio recordings made at varying distances from the crowing rooster show that at a distance of 0.5 m sound pressure levels already drop to 102 dB. Micro-CT scans of a rooster and chicken head show that in roosters the auditory canal closes when the beak is opened. In hens the diameter of the auditory canal only narrows but does not close completely. A morphological difference between the sexes in shape of a bursa-like slit which occurs in the outer ear canal causes the outer ear canal to close in roosters but not in hens.
Language
English
Source (journal)
Zoology : analysis of complex systems
Publication
2018
ISSN
0944-2006
Volume/pages
126 (2018) , p. 65-70
ISI
000436226300008
Pubmed ID
29373167
Full text (Publisher's DOI)
Full text (open access)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 02.08.2018
Last edited 06.09.2021
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