Salt,A. Hullar,T. Responses of the Ear to Low Frequency Sound, Infrasound & Wind Turbines
Alec N. Salt, Timothy E. Hullar
Elsevier, Hearing Research, June 2010
Infrasonic sounds are generated internally in the body (by respiration, heartbeat, coughing, etc.) and by external sources, such as air conditioning systems, inside vehicles, some industrial processes and, now becoming increasingly prevalent, wind turbines. It is widely assumed that infrasound presented at an amplitude below what is audible has no influence on the ear. In this review, we consider possible ways that low frequency sounds, at levels that may or may not be heard, could influence the function of the ear. The inner ear has elaborate mechanisms to attenuate low frequency sound components before they are transmitted to the brain. The auditory portion of the ear, the cochlea, has two types of sensory cells, inner hair cells (JHC) and outer hair cells (OHC), of which the IHC are coupled to the afferent fibres that transmit “hearing” to the brain.”