Effects of Long-Term Speech-in-Noise Training in Air Traffic Controllers and High Frequency Suppression. A Control Group Study

Abstract

OBJECTIVE:To evaluate 1) if air traffic controllers (ATC) perform better than non-air traffic controllers in an open-set speech-in-noise test because of their experience with radio communications, and 2) if high-frequency information (>8000 Hz) substantially improves speech-in-noise perception across populations. MATERIALS and METHODS:The control group comprised 28 normal-hearing subjects, and the target group comprised 48 ATCs aged between 19 and 55 years who were native Spanish speakers. The hearing -in-noise abilities of the two groups were characterized under two signal conditions: 1) speech tokens and white noise sampled at 44.1 kHz (unfiltered condition) and 2) speech tokens plus white noise, each passed through a 4th order Butterworth filter with 70 and 8000 Hz low and high cutoffs (filtered condition). These tests were performed at signal-to-noise ratios of +5, 0, and −5-dB SNR. RESULTS:The ATCs outperformed the control group in all conditions. The differences were statistically significant in all cases, and the largest difference was observed under the most difficult conditions (−5 dB SNR). Overall, scores were higher when high-frequency components were not suppressed for both groups, although statistically significant differences were not observed for the control group at 0 dB SNR. CONCLUSION:The results indicate that ATCs are more capable of identifying speech in noise. This may be due to the effect of their training. On the other hand, performance seems to decrease when the high frequency components of speech are removed, regardless of training.

Habilidades auditivas de figura-fundo e fechamento em controladores de tráfego aéreo

“…The result of this indirect auditory training in ATCs is in agreement with those of recent studies (26,27) .…”

“…It is believed that the performance of the ATCs in the applied tests was not affected by stress owing to a compensatory cognitive effort (28,29) . Thus, professional training makes ATCs less vulnerable to attention disturbances (29) thanks to the professional demands that make them more adept at coping with adversities in the acoustic environment trough cognitive effort (26)(27)(28)(29) .…”