背景噪声对人感知声音时间信息的影响

INFLUENCE OF BACKGROUND NOISE ON THE PERCEPTION OF SOUND TEMPORAL INFORMATION

对声音时间信息的分辨在人和动物感知声音信息的过程中至关重要。在自然声环境中,声音信息总处于一定的噪声背景下。文章以间隔探测阈值为指标测定了人对纯音和噪声的间隔探测阈值,以及持续噪声背景对间隔探测阈值的影响。声音信号采用1000～10000Hz的纯音信号和白噪声信号,声音强度为70dBSPL。背景噪声为持续白噪声,强度分别为45、55、65dBSPL。结果表明,对纯音信号,随着背景噪声强度增加,间隔探测阈值有升高的趋势。对噪声信号来说,45、55dBSPL的背景噪声对噪声信号的间隔探测阈值无显著影响,但65dBSPL的背景噪声使间隔探测阈值显著升高。研究结果提示,背景噪声能够在一定程度上影响人对声音时间信息的感知,影响的程度与背景噪声的强度有关。

Discrimination of sound temporal information is crucial in the perception of sound for human and animals. In natural acoustical environments, sound information is always accompanied by background noise. The present study measured the gap detection threshold for pure tone and white noise of 6 subjects in quiet environments, and in continuous background noise environments, respectively. The pure tone signals were within the frequency range of 1000-10000 Hz, and the noise signal was white noise. The sound level of these signals was at 70 dB SPL. The continuous background noise was white noise with three levels, i.e., 45, 55, and 65 dB SPL, respectively. The results showed that, the gap detection thresholds for pure tone signals were increased with increasing background noise level. For noise signals, the gap detection thresholds were not significantly influenced when the background noise levels were at 45 and 55 dB SPL; however, the gap detection thresholds were significantly increased when the background noise level was at 65 dB SPL. These results suggest that background noise can influence the perception of sound temporal information, and the degree of influences is related to background noise level.