What does noise affect?
- Noise Effects & Mitigation
- How does Noise affect People?
- How does Noise affect Domestic Animals and Wildlife?
- Other Noise Related Effects
In this section, we will examine how noise effects domestic animals such as cattle, swine, and poultry as well as wildlife. Wildlife includes mammals and birds such as raptors and wading/shorebirds.
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Hearing is critical to an animal's ability to:
- Seek mates and reproduce
- Hunt and forage
Studies on possible effects of jet aircraft noise and sonic booms on wildlife have been done. Behavioral effects have been pretty well described. However, the larger environmental issues have not been well developed. This reduces the potential for drawing conclusions about the effects on animal populations.
The consequences that physiological effects may have on behavioral patterns are vital to understanding the long-term effects of noise on wildlife. Questions remain regarding the effects (if any) on:
- Predator-prey interactions
- Reproductive success
- Intra-inter specific behavior patterns
Animal species differ greatly in their responses to noise. Noise effects on domestic animals and wildlife are classified as:
- Direct, physiological changes to the auditory system
- May include masking or interfering with normal animal functions
- Other primary effects are not as likely. These include ear drum rupture or temporary/permanent hearing threshold shifts.
- May include non-auditory effects such as
- Stress and hypertension
- Behavioral modifications
- Interference with mating or reproduction
- Impaired ability to obtain adequate food, cover, or water
- These are the direct result of primary and secondary effects. Included are population decline and habitat loss. However, most of the effects of noise are mild enough that they may never be detectable in changes in population size.
- Other things in their environment also influence secondary and tertiary effects. These include predators, weather, changing prey base, and ground-based disturbance. This hinders the ability to identify the ultimate cause of the decline.
A great deal of research was conducted in the 1960's and 1970's on the effects of aircraft noise on the public. This included the potential for adverse environmental impacts. Overall, the research suggests that species differ in their response to:
- Various types of noise
- Durations of noise
- Sources of noise
Many scientific studies have investigated the effects of aircraft noise on wildlife. Some have focused on wildlife "flight" due to noise. Animal responses to aircraft are influenced by many things, including:
- Proximity (both height above the ground and lateral distance)
- Engine noise
- Flight profile
- Radiated noise
The type of aircraft and type of flight mission may also produce different levels of disturbance, with varying animal responses.
Consequently, it is difficult to generalize animal responses to noise disturbances across species. However, a general animal behavioral reaction to aircraft noise is the startle response. The strength and length of the startle response appears to be dependent on:
- which species is exposed
- whether there is one animal or a group
- whether there have been some previous exposures
Other responses include:
- Movement of the head in the apparent direction of the noise source
Click here for a listing of the relevant research.