Otoacoustic emissions in call centre operators

The objective of this study was to analyze the risk of noise-induced hearing loss (NIHL) in call center operators. Distortion product otoacoustic emissions (DPOAEs) and transient-evoked otoacoustic emissions (TEOAEs) were measured in 49 workers, aged 2247 years, employed at one call center. All subjects were also inquired about their hearing-related symptoms and risk factors for NIHL. Sound pressure levels generated by the communication headset were determined using the artificial ear technique specified in CSA Z107.56-18. The background noise prevailing in offices was also measured according to PN-N-01307:1994 and PN-EN ISO 9612:2011. Individual daily noise exposure levels in call center operators ranged from 67 to 84 dBA (1090th percentile). DPOAEs were present bilaterally in 58.3% of study subjects. Reproducibility of TEOAE above 60% and signal-to-noise ratio higher than 6 dB (in all analyzed frequency bands) were found in 47.9% and the 20.8% of employees, respectively. When analyzing the impact of age, gender and noise exposure on hearing ability, both recorded DPOAEs and TEOAEs showed tendency towards better hearing in females vs. males and younger vs. older operators. The impact of daily noise exposure level on the otoacoustic emissions was less evident. Nevertheless, some of call center operators reported hearing-related symptoms.