Noise and Vibration Report - Transnet

ENVIRO-ACOUSTIC RESEARCHSCOPING NOISE REPORT – TRANSNET: SWAZI RAIL LINK – DAVEL YARD TO NERSTON RSA ROUTE6 METHODOLOGY: NOISE IMPACT ASSESSMENT ANDSIGNIFICANCE6.1 NOISE IMPACT ON ANIMALS 3A great deal of research was conducted in the 1960's and 1970's on the effects of aircraftnoise on animals. While aircraft noise have a specific characteristic, the findings shouldbe relevant to most noise sources.Overall, the research suggests that species differ in their response to:• Various types of noise• Durations of noise• Sources of noiseA general animal behavioural reaction to aircraft noise is the startle response. However,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 exposuresUnfortunately, there are numerous other factors in the environment of animals that alsoinfluence the effects of noise. These include predators, weather, changing prey/food baseand ground-based disturbance, especially anthropogenic. This hinders the ability todefine the real impact of noise on animals.From these and other studies the following can be concluded:• Animals respond to impulsive (sudden) noises (higher than 90 dBA) by runningaway. If the noises continue, animals would try to relocate.• Animals of most species exhibit adaptation with noise, including aircraft noise andsonic booms;• More sensitive species would relocate to a more quiet area, especially species thatdepend on hearing to hunt or evade prey, or species that makes use ofsound/hearing to locate a suitable mate.• Noises associated with helicopters, motor- and quad bikes significantly impact onanimals.3 Report to Congressional Requesters, 2005; USEPA, 1971; Autumn, 2007; Noise quest, 2010P a g e | 30