Published online by Cambridge University Press: 27 May 2011
Noise exposure in the workplace and the recreational environment probably accounts for more new cases of tinnitus and hearing loss than all other causes combined. To an increasing degree, preemployment audiograms of late teenagers and those in their early twenties show noise-induced, sensorineural ‘notches’ greatest at 4000 or 6000 Hz with partial or complete recovery at 8000 Hz. Word discrimination tests, as typically evaluated in a clinical situation, show essentially normal findings although more difficult measures of consonant discriminations such as the California Consonant Test or conventional speech tests in a background of noise often demonstrate impaired word discrimination ability.