An Integrated Approach to the Creation of a Humpback Whale Hearing Model

• Main Authors: Helweg, D. A., Houser, D. S., Moore, P. W.
• Other Authors: SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO CA
• Format: Text
• Language: English
• Published: 2000
• Subjects: Anatomy and Physiology; Bionics; *HEARING; *WHALES; MATHEMATICAL MODELS; EXPOSURE(GENERAL); SENSITIVITY; WEIGHTING FUNCTIONS; BANDPASS FILTERS; UNDERWATER SOUND; EAR; ACOUSTIC PROPERTIES; HUMPBACK WHALES; INNER EAR; SERDP COLLECTION; SERDP(STRATEGIC ENVIRONMENTAL RESEARCH AND DEVELOPMENT PROGRAM); WUDN308415; WUMM79; baleen whales; Humpback Whale; Megaptera novaeangliae
• Online Access: http://www.dtic.mil/docs/citations/ADA384563; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA384563

Human activity can generate underwater signals potentially capable of injuring or altering the behavior of mysticetes (baleen whales). Little information exists on mysticete hearing and this information is not likely to be obtained in the near future. In order to provide the Navy with tools helpful in predicting the potential impact of anthropogenic underwater sound on mysticetes, a model of humpback whale (Megaptera novaeangliae) hearing was constructed. Anatomical indices of hearing taken from the inner ear of a humpback were used to create a frequency-position function (i.e., predict the range of hearing). Auditory sensitivity and frequency-position functions of the cat and human were then integrated with the humpback frequency-position function to create an audiogram for the humpback. The predicted audiogram was typically mammalian in shape and suggested a maximum acoustic sensitivity between 2 and 6 kHz. A bandpass filter model of humpback hearing, consisting of a series of overlapping pseudo-Gaussian filters, was created and the model design varied via an evolutionary program to optimize model sensitivity. Agreement between model sensitivity and predicted humpback sensitivity always exceeded 90 percent. The computational model of humpback whale auditory sensitivity is used as an auditory weighting function in assessment of sound exposure.