语声特性及声场因素对老年人警报语声可懂度和主观感受的影响

The effect of characteristics of voice and sound field on the elderly’s speech intelligibility and subjective evaluation of voice alarms

警报语声广播是紧急情况时提高建筑物内疏散效率的有效手段。通过实验室研究的方法,研究了语声特性及声场因素对老年群体警报语声可懂度和主观感受的影响。主观感受选取了听声容易程度和感知紧迫性两个维度。研究结果表明,老年人警报语声可懂度和听声容易程度评价主要受语速、信噪比和混响时间的影响,且呈现一致的变化趋势,即随着语速和混响时间降低以及信噪比的增加,老年人可懂度和听声容易程度得分均升高,而声压级(最低设置为60 dB)、有无警铃和噪声类型没有显著影响。感知紧迫性随语速和声压级的增加而显著增加,信噪比、混响时间及有无警铃声对感知紧迫性并无显著影响。采用人声播报的警报语声其可懂度和感知紧迫性显著高于合成声。比较老年人和年轻人群体的结果发现,在语速、声压级和噪声类型对主观评价的影响上有显著差异。为建立老年人理想且安全的声环境,应采用人声播报并适当降低语速以保证可懂度,同时混响及信噪比条件两方面的改善都是必要的。

Voice alarm broadcast is an effective method to improve evacuation efficiency in emergency situations.This paper mainly studied how the voice and sound field factors affect the intelligibility and subjective evaluation of the voice alarms in the elderly group with the laboratory experiment.The subjective evaluation included the evaluation of ease of listening and the perceived urgency.The results showed that the elderly’s speech intelligibility and ease of listening were mainly affected by speech rate,signal-to-noise ratio(SNR)and reverberation time(RT).The elderly’s intelligibility score and ease of listening rating showed a consistent trend when changing with these factors:they both increased with speech rate and RT getting lower,and they increased with the increase of SNR.However,sound pressure level(SPL)above 60 dB,whether there is tone before the voice and noise type had no significant effect on elderly’s intelligibility score and ease of listening rating.The perceived urgency increased with the increase of the speech rate and SPL,but the SNR,RT and whether there is tone before the voice had no significant effect on it.The intelligibility and perceived urgency to voice alarms broadcast in human voice were significantly higher than those to the alarms broadcast in the synthetic voice.The analysis on group differences showed that there were significant differences in the intelligibility and subjective evaluation affected by speech rate,SPL and noise type between young and old groups.In order to establish an ideal and safe acoustic environment for the elderly,it is necessary to adopt human voice broadcasting and reduce speech rate to ensure intelligibility.Meanwhile,it is necessary to improve the condition of reverberation and noise.