Auditory fatigue among call dispatchers working with headsets

Objectives: To determine whether call center dispatchers wearing headsets are subject to auditory fatigue at the end of a work shift. Material and Methods: Data was gathered at times when call centers were busiest. All call operators wore a headset for up to 12 h. Acoustic environment and noise exposure under the headset were continuously recorded during the entire work shift. Variations in auditory parameters were assessed using pure-tone air-conduction audiometry and an objective test based on distortion product otoacoustic emissions-contralateral suppression of distortion product otoacous-tic emission (DPOAE) amplitudes (EchoScan test). Thirty-nine operators and 16 controls, all volunteers, were selected from 3 call centers (sales, assistance, and emergency) where all cognitive tasks were accomplished by phone and on computers. Results: No acoustic shock was detected during the investigation. The highest normalized noise exposure (daily noise exposure level-L EX,8 h) measured was 75.5 dBA. No significant variation in auditory performances was detected with either pure-tone air-conduction audiometry or the EchoScan test. Nevertheless, dispatchers expressed a feeling of tiredness. Conclusions: For an equivalent diffuse field noise exposure, the use of a headset does not seem to worsen auditory fatigue for call center operators. The dispatcher's fatigue was probably due to the duration of the work shift or to the tasks they performed rather than to the noise exposure under a headset.