geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Structure and function in whale ears


, : Structure and function in whale ears. Bioacoustics 8(1-2): 103-135

Ultrasonic echolocation abilities are well documented in several dolphin species, but hearing characteristics are unknown for most whales. Vocalization data suggest whale hearing spans infra- to ultrasonic ranges. This paper presents an overview of whale ear anatomy and analyzes 1) how whale ears are adapted for underwater hearing and 2) how inner ear differences relate to different hearing capacities among whales. Whales have adaptations for rapid, deep diving and long submersion; e.g., broad-bore Eustachian tubes, no pinnae, and no air-filled external canals, that impact sound reception. In odontocetes, two soft tissue channels conduct sound to the ear. In mysticetes, bone and soft tissue conduction are likely. The middle ear is air-filled but has an extensible mucosa. Cochlear structures are hypertrophied and vestibular components are reduced. Auditory ganglion cell densities are double land mammal averages (2000-4000/mm). Basilar membrane lengths range 20-70 mm; gradients are larger than in terrestrial mammals. Odontocetes have 20-60% bony membrane support and basal ratios gt 0.6, consistent with hearing gt 150 kHz. Mysticetes have apical ratios lt 0.002 and no bony lateral support, implying acute infrasonic hearing. Cochlear hypertrophy may be adaptive for high background noise. Vestibular loss is consistent with cervical fusion. Exceptionally high auditory fiber counts suggest both mysticetes and odontocetes have ears "wired" for more complex signal processing mechanisms than most land mammals.

US$19.90

DOI: 10.1080/09524622.1997.9753356


Other references

Tavassoli, M., 1974: Arterial structure of bone marrow in the rabbit with special reference to the thin-walled arteries. Acta Anatomica 90(4): 608-616

Liang Jian Jie; Sherriff Barbara L., 1993: Lead exchange into zeolite and clay minerals; a (super 29) Si, (super 27) Al, (super 23) Na solid-state NMR study. Geochimica et Cosmochimica Acta 57(16): 3885-3894

Pantovic, A.; Arsikin, K.; Kosic, M.; Ristic, B.; Trajkovic, V.; Harhaji-Trajkovic, L., 2017: Data supporting the inability of indomethacin to induce autophagy in U251 glioma cells. Autophagy, a catabolic process involving intracellular degradation of unnecessary or dysfunctional cellular components through the lysosomal machinery, could act as a prosurvival, as well as a cytotoxic mechanism (Parzych and Klionsky, 2014) [1]....

Hildebrandt, J., 1968: Die Wirk-samkeit von BilevonR M gegen unreife und geschlechtsreife Stadien von Fasciola gigantica in kunstlich infizierten Schafen. 65 sheep experimentally infected with Fasciola gigantica were treated with Bayer 9015 (Bilevon M) at dose levels of 3, 4 and 6 mg. of active constituent per kg. body-weight. Treatment with 3 mg. per kg. at 16 weeks after infection showed a reducti...

Chao, W.; Jin, Q.; Zhi-Yong, G.; Li, Z.; Xiao-Chen, L., 2008: Vertical distributions of phosphorus fractions in sediments of three typical shallow urban lakes in PR China. Sediment cores were sampled from three typical shallow urban lakes in China. The Standards, Measurements and Testing (SMT) programme, proposed by the European Commission, was employed to characterize the vertical distributions of phosphorus fracti...

Silverdale, N.; Katz, J., 2005: The impact of a distance learning death and dying course: an analysis of student self-reported changes. Educational programmes are under way to improve knowledge, awareness and skills in holistic end-of-life care. Not all people can access education and continued professional development in a conventional face-to-face setting. The UK Open University...

Thomas, A.; Hanel, B.; Marott, J.L.; Buchvald, F.; Mortensen, J.; Nielsen, K.G., 2017: Correction: The Single-Breath Diffusing Capacity of CO and NO in Healthy Children of European Descent. [This corrects the article DOI: 10.1371/journal.pone.0113177.].

Zavaglia C.; Brivio M.; Losacco E.; Onida L., 1992: Protein diets and hepatic encephalopathy in liver cirrhosis. Hepatic encephalopathy is a neuropsychiatric syndrome, which can occur in the clinical course of acute (fulminant) or chronic hepatic failure of various aetiology; reversible metabolic abnormalities without neuronal structural changes are frequent...

Van Der Eb, A.J., 2000: First A J van der Eb Honorary Lecture Viruses as tools for cancer gene therapy Promises and problems. Cancer Gene Therapy 7(8): 1207, August

Thomas Jose Eduardo, 1988: Pre-balancing of amplitude spectra from field meters for obtaining high resolution seismic data. Revista Brasileira de Geofisica 7(1): 69