Factors affecting Hearing and Acoustic pollution:
  
  • Acoustic sensitivity profile or auditory range (the range of frequencies and the minimum intensity (loudness) of each frequency that the animal can normally detect in the absence of any damage or pathology).
  • “Masking” Form of noise pollution for which there will be no physical evidence of damage. Masking is when the environmental noise level is intense enough and of the right frequency range to cover-up pr “mask” the normal hearing range of the animal. In this case, an animal in the environment will be functionally unable to hear what it may need to hear because of the masking noise- but the animal will not be deaf.
  • “Deafness” Is the loss of normal acoustic sensitivity due to damage or some pathologic process. Some damage will be detectable grossly (head trauma, haemorrhage, parasites) mostly however, inner ear damage will be detected only histologically on specimens that were well prepared for the microscope. For live animals, loss of hearing sensitivity will only be detected by functional testing and neurologic examination.
  • Other inner ear function- Affected by vibration (sound wave) injury. For example vestibular function (balance) may also be damaged by high intensity, low frequency (explosions).

 

Source:

C-TURTLE List server:

Lawrence Herbst DVM MS PhD dipACLAM
Associate Professor
Albert Einstein College of Medicine

Institute for Animal Studies, Albert Einstein Coll
1300 Morris Park Avenue
Bronx, NY 10461 US

Other references:

Bartol, S., Musick, J., Lenhardt, L. (1999) Auditory evoked potentials of the loggerhead sea turtle (Caretta caretta) Copeia (3) p.p. 836-840.