ABSTRACT
Hearing loss induced by impulse noise was compared with that induced by continuous or mixed types of noise. Three industrial groups of workers exposed to these three types of noise were studied together with a control group. Results showed that impulse group had the highest threshold level values [TLVs] at 6 kHz [27. 1 dB] and 4 kHz [26.2 dB] in the left ear. Continuous group had the highest TLVs at 6 kHz; the values were 17.1 dB in left ear and 16.8 in right ear. Mixed group had the highest TLVs at 6 kHz in left ear [20.7 dB] and at 4 kHz in right ear [19.8 dB]. Control group had highest TLVs at 8 kHz [10.3 dB] and 6 kHz [8.8 dB] in left ear. Impulse group had the highest TLVs, while the control group had the lowest values. We concluded that exposure to impulse noise is more harmful to hearing and causes more serious hearing loss than continuous or mixed noise, and that the regions mostly affected are at 4 and 6 kHz