The effect of listener head orientation on speech intelligibility in noise

Abstract

The signal-to-noise ratio at one ear is progressively improved by orienting the head away from the target sound source by up to 65 degrees, so facing the speaker in a sidelong way may be an effective listening tactic in noisy listening situations. In a listening configuration that optimized this effect in a sound-treated room, speech reception thresholds improved by up to 10 dB with head orientation, but without instruction few listeners adopted the tactic. Audio-visual presentation of the target speech further suppressed its use [Grange and Culling, J. Acoust. Soc. Am. 139, 703-712 (2016)]. Audio-visual presentation produced an additive lip-reading benefit that was unaffected by a head orientation 30 degrees away from the speaker. A head-orientation benefit was also observed in realistic listening conditions, simulated over headphones. Binaural room impulse responses from a real restaurant were used to simulate listening at six different tables with nine concurrent interferers. Head orientation of 30 degrees produced a mean benefit of 1 dB for speech interferers and 1.3 dB for noise interferers [Grange and Culling, J. Acoust. Soc. Am. 140, 4061-4072 (2016)]. These results suggest that listeners would benefit from advice to orient away from the speaker while maintaining eye contact.