Assessment of risk of noise induced hearing damage

Presently, there exists a number of standards for how much noise humans may be exposed to in their working environment. There is however one big problem with these standards: They do not normally take into account what kind of noise it is. Numerous investigations have shown that the degree and type of hearing damage depends on the physical properties of the noise. Some of these properties are parameters like peak sound pressure level, mean sound pressure level, total exposure time, prevalence of peaks in sound pressure level, relationship between peak and background sound pressure levels, and the frequency contents of the noise. Furthermore, there is a certain variation in how susceptible the human ear is towards noise damages. This project investigates human hearings' response to noise with the aim of nding physical parameters which can describe the risk of hearing damage given a certain noise, and in this manner improving the existing noise assessment standards. Moreover, it is desired to investigate if it is possible to reduce the variation in susceptibility towards noise by taking people's individual physical characteristics into account during the assessment of temporary changes of the auditory function (thresholds and otoacoustic emissions). Last but not least, it would be natural to apply some of these results in developing methods for early determination of beginning hearing loss. Supported by STVF/FTP.