环境噪声对声信号频率辨别阈的影响

The effect of environmental noise on sound signal frequency discrimination

目的 通过环境噪声对人体接收不同声信号频率辨别阈影响的试验，寻找某种具有抗噪声干扰的特殊信号．为研究抗噪声言语通讯装置提供理论依据。方法 选取３种调制波，即纯音调频信号、调幅调频信号和方波，作为测试声信号，采用阈上测试法，以阈上 ４０ ｄＢ信号辨别阈值为对照，分别测定Ｓ（信号）／Ｎ（噪声）比为０，－５，－１０的频率辨别阈。结果 以上 ３种信号的频率辨别阈为方波最佳，调幅调频波次之，纯音信号最差。结论 本试验为抗噪声言语通讯开拓了新途径。言语若采用经调制后的方波或调幅波传递，将会获得满意的可懂度。

Objective Experiment of the effect of environmental noise on different sound signal frequency discrimination threshold in human subjects was carried out with the aim of finding a specific anti-noise signal so as to provide theoretical basis of developing an anti-noise speech communication device. Methods Theree kinds of modulating sound waves including frequency modulating pure tone signal (f) .amplitude and frequency modulating signal (fam) and frequency modulating square wave signal (fr) were used. Adopting over threshold value measurements and taking discrimination values above threshold 40 dB as normal control.the signal/noise(S/N) frequency discrimination values of 0, ?5 and ?10 were measured respectively. Results The best frequency discrimination signal of the three was square wave with amplitude modulating wave second and pure tone wave third. Conclusions This experiment opened a new way of anti-noise speech communication. With square wave or amplitude modulating wave transmission,the speech communication will have satisfactory intelligibility.