飞机舱音记录器背景声的联合时频分析研究

飞机舱音记录器记录的舱音主要是由话语音、噪声和具有不同物理意义的背景声组成的复杂混合体,用传统的辨听和分析方法难以获取较多的舱音特征参数。本文以一个舱音记录器记录的主告警声为例,针对传统短时傅立叶变换在舱音辨听、分析的不足,将联合时频分析引入到飞机舱音分析中,扩展了舱音分析方法。对比分析结果表明:时频分布及其重排,在时频分辨率、时频凝聚性、交叉项干扰的抑制上各有所长,都适合分析非平稳舱音背景声,从而为飞行事故调查提供一种值得采用的方法。

United time-frequency analysis for background sounds of cockpit voice recorder

Cockpit voice recorder(CVR)in aircraft records many cockpit voices,such as the speaker voices,noises,background sounds with various special meanings.However, cockpit voices’complexity exacerbates analysis difficulty when traditional differentiating & hearing methods are used,because more cockpit voices’characteristics are not resolved sufficiently.According to the shortcoming of analysis by traditional short time Fourier transformation(STFT),the methods of united time-frequency analysis is introduced in this paper.Comparisons show that time-frequency distribution and its reassigned versions have each advantage for time-frequency resolution,time-frequency cohesion and immunity of cross term interference,and are adaptable to analyze the non-stationary cockpit background sounds and offer a reference of method for flight accident investigations.