A predicted humpback whale hearing curve based on modified behavioral observation audiometry data
Year: 2025
Type: article
Abstract: Despite decades of research, little capability exists to reliably predict the impact of ocean noise on marine mammals. 1 Noise impact predictions require knowing the frequencies marine mammals can hear and their sensitivity to those sounds (e.g., the hearing threshold, or the susceptibility to noise-induced hearing loss). For odontocetes and pinnipeds, these are well documented using behavioral methods, where the animal is trained to respond to an audible signal, 2 or auditory evoked potential (AEP) methods, where the neural response of the brain is measured. 2 Both the hearing range and sensitivity for all species of baleen whales are currently unknown. We used a behavioral observation audiometry (BOA) hearing test method in free-ranging humpback whales ( Megaptera novaeangliae ). BOA is an established hearing test method used in human children incapable of understanding and carrying out the verbal instructions necessary to perform a hearing test. 3 A minimum response level (MRL) is calculated from the lowest sound levels to which the subject shows a response. 3 , 4 , 5 It offers a useful estimate of hearing sensitivity when other options are unavailable. Here, this method was used to generate a predicted hearing curve for humpback whales, which was compared with an anatomically derived curve based on studies of the cochlear and middle ear. 6 , 7 , 8 The predictive hearing curve presented here, along with new evidence of higher frequency hearing, will assist regulators and stakeholders in assessing the potential impact of anthropogenic sound on large whales.
Source: Current Biology
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $7,030
Funder: Office of Naval Research
OpenAlex ID: W7117106499