2019_programme: HEARING MODELS IN TWO SPECIES OF BALEEN WHALES

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  • Session: 03. Acoustic Monitoring of Ocean Environments and Processes: Biology, Ecology, Geophysics and Man-made activities
    Organiser(s): Ratilal Purnima, Miksis-Olds Jennifer
  • Lecture: HEARING MODELS IN TWO SPECIES OF BALEEN WHALES
    Paper ID: 909
    Author(s): Ketten Darlene R, Tubelli Andrew A, Zosuls Aleks, Voysey Graham
    Presenter: Ketten Darlene
    Presentation type: oral
    Abstract: Vocalization studies suggest baleen whales (Mysticeti) may be the marine mammals most liable to impacts from low frequency sound sources. For multiple practical reasons there are at present no in vivo measures of mysticete hearing. Modelling is a well-established alternative for estimating species-specific hearing for risk assessments and provides guides for optimizing playback signals as well as insights for developing effective electrode and source placements for evoked potential (AEP) measures. Models also allow exploration of how auditory system variations relate to hearing and impact susceptibility.\nIn this study, we produced models of auditory characteristics for minke (Balaenoptera acutorostrata) and humpback (Megaptera novaeangliae) whales. Control data consisted of comparing model results for bottlenose dolphin (Tursiops truncatus) and harbor porpoises (Phocoena phocoena) with live animal audiograms. Micro CT scanning, dissection, and histology measures of inner ears produced inner ear frequency position maps (FPM) that were compared with nanoindentation basilar membrane stiffness measures to derive total hearing ranges and peak frequency of noise induced hearing loss notches (NIHL) in each species. Middle ear measurements of frequency response and stiffness at the stapes footplate were coupled with the morphometrics and material properties of the ossicular chain and associated soft tissues for input to finite element models (FEM) to obtain middle ear transfer functions (METF) in the whales. Frequency response differences were measured also for stimulation of the glove finger vs tympanic bulla to assess bone vs tympanic membrane transfer efficiency. Peak responses differ in each of the baleen whale species but were generally between 20Hz to 5 kHz in these two species with maximal functional hearing ranges of 50 Hz to 33 kHz. The study was supported by the Joint Industry Programme on Sound and Marine Life, the Hanse Wissenschaftskollegg ICBM Fellowship and the Helmholtz International Fellow research programs.
  • Corresponding author: Dr Ketten Darlene
    Affiliation: (1) Biomedical Engineering, The Hearing Center, Boston University; (2) Woods Hole Oceanographic Institution
    Country: United States
    e-mail:

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