The effect of aircraft noise on speech intelligibility at outdoor living spaces

摘要

Aircraft noise reduces the potential for outdoor living spaces to provide rest and recreation. One adverse effect is interference with speech communication, including mobile phone conversations and radio listening. Previous research on how noise interferes with speech intelligibility has focused on indoor environments, such as class rooms, and it is unclear how well results from this research generalize to outdoor environments. To explore this, we reproduced first order ambisonic recordings of aircraft noise in a pergola located outdoors in an area with low background level (45-50 dB L_(Aeq)). Lists of phonetically balanced words (average level: 54 dB L_(Amax,slow)) were reproduced simultaneously with noise from aircraft over flights, ranging from 72 to 84 dB L_(Amax,slow). Twenty young adult listeners, with normal hearing, were tested individually. They were seated in the pergola and were asked to write down each presented word. The results suggested that aircraft noise, at outdoor living spaces, impairs speech intelligibility at signal-to-noise ratios of 0 dB or less. Calculations of the speech signal's partial loudness, showed impaired intelligibility for loudness levels below 40 dB phon. These results apply to listeners with normal hearing and for speech intelligibility of single words in noise.