A Novel Miniaturized Noise Level Dosimeter for Investigation and Prevention of Human Hearing Loss

A novel noise level dosimeter for the measurement of fast, bang-like noise of high level (up to 180 dB) and fast rise time (20 mus) is presented. At present, noise related hearing loss is still referred mainly to the level of noise and the exposition time. However, several studies show that an entire research of hearing loss caused by bangs is still missing. The presented noise level dosimeter has been developed for such studies. To achieve a good sensitivity over a large sound level range from 65 dB to 180 dB the sensor was split into two sub sensors: a low-level sensor covers the region from 65-150 dB, a high-level sensor covers the region 120-180 dB, with an overlapping operation from 120 dB to 150 dB sound level. The sampling is done by an analog/digital converter. The data are stored on an SD-Card and are transferred via USB to a computer for the evaluation of the measurement. The sensors are simulated by finite element simulation with COMSOL Multiphysics(r) software and realized using SOI technology with the benefit of well-defined membrane thickness (5 micrometer or 10 micrometer). First realized sensors were characterized and the response to high level impulses is in good agreement with the simulations.