Noise Effect

What does noise affect?

Some physiological/behavioral responses have been described in a small percentage of studies. These responses include:

  • increased hormonal production
  • increased heart rate
  • reduction in milk production

A majority of the studies focusing on these types of effects have reported short-term or no effects. The relationships between physiological effects and how species interact with their environments have not been thoroughly studied. Therefore, the ecological issues of the physiological effects of jet aircraft noiseand behavioral changes are not well understood.

Animal species exhibit a wide variety of responses to noise. So, it is difficult to take a broad view of animal responses to noise disturbances. Also, it is difficult to draw conclusions across species. This is because reactions to jet aircraft noise appear to be species-specific.

Consequently, some animal species may be more sensitive than others. Also, they may exhibit different forms or strengths of responses. For instance, wood ducks appear to be more sensitive and more resistant to adaptation to jet aircraft noise than Canada geese. Similarly, wild ungulates seem to be more easily disturbed than domestic animals.

The literature does suggest that common responses include the "startle" or "fright" response. It has also been reported that the strength and duration of the startle responses decrease with the number and frequency of exposures. This suggests no long-term harmful effects. The majority of the literature suggests that domestic and wildlife species exhibit adaptation after repeated exposure to jet aircraft noise and sonic booms. Animal responses to aircraft noise appear to be somewhat dependent on or influenced by the craft's:

  • size
  • shape
  • speed
  • proximity (vertical and horizontal)
  • engine noise
  • color
  • flight profile

Helicopters also appear to cause greater strengths and durations of disturbance behavior compared to fixed-wing aircraft.

Some studies showed that animals that were previously exposed to jet aircraft noise showed greater degrees of disturbance to other objects creating noise. This includes objects such as:

  • boats
  • people
  • objects blowing across the landscape.

Other factors influencing response to jet aircraft noise may include:

  • wind direction
  • wind speed
  • local air turbulence
  • landscape structures (that is, the amount and type of vegetative cover) and, in the case of bird species, whether the animals are in the incubation/nesting phase

References:

Dufour, P.A. 1980. Effects of Noise on Wildlife and Other Animals: Review of Research Since 1971. U.S. Environmental Protection Agency.

Gladwin, D.N., K.M. Manci, and R. Villella. 1988. Effects of Aircraft Noise and Sonic Booms on Domestic Animals and Wildlife. Bibliographic Abstracts. NERC-88/32. U.S. Fish and Wildlife Service National Ecology Research Center, Ft. Collins, Colorado.

Wever, E.G., and J.A. Vernon. 1957. Auditory Responses in the Spectacled Caiman. Journal of Cellular and Comparative Physiology, Vol. 50, pp. 333-339.