基于音频均衡器的语言清晰度测试声源设计

Design of sound source for speech intelligibility test based on audio equalizer

语言清晰度主要用于评价厅堂或者扩声系统的声音质量,为了实现对厅堂语言清晰度的自动测量,提高测量的效率,设计了一种用于语言清晰度测量的测试声源。该声源由控制器单元和扬声器单元两部分组成,控制器以MCU作为主控,内置经过调制的STIPA信号。声源经过测量放大器对声压级的校准之后,由MCU读取STIPA信号并通过音频均衡器算法做均衡处理,由功率放大电路驱动扬声器进行播放。经过均衡处理的扬声器,在100 Hz~10 kHz范围内,其播放声信号的频响平坦度可以达到±1 dB,满足厅堂或者扩声系统对声源语言清晰度测量的要求。利用该声源发出STIPA信号,STI分析仪测量STI指数,可以实现对厅堂或者扩声系统语言清晰度的测试。

Speech intelligibility is mainly used to evaluate the sound quality of the hall or sound reinf⁃orcement system.In order to realize the automatic measurement of speech intelligibility in the hall and improve the measurement efficiency,a test sound source for speech intelligibility measurement is designed.The sound source is composed of a controller unit and a speaker unit.The controller unit uses MCU as the main control and has a built⁃in modulated STIPA signal.After the test sound source is corrected by the measuring amplifier to the frequency response,the STIPA signal is read by the MCU and equalized by the audio equalizer algorithm,and the speaker unit is driven by the power amplifier circuit to play.In the range of 100 Hz~10 kHz,the frequency response flatness of the sound signal played by the equalized speaker can reach±1 dB,which meets the requirements of the hall or sound reinf⁃orcement system for the sound source of speech intelligibility measurement.The STIPA signal is sent out by the sound source,and the STI index is measured by the STI analyzer,so that the speech intelligibility test of the hall or sound reinforcement system can be realized.