The relationship between speech reception threshold and the assessment of annoyance caused by different environmental noises

Noise disturbs communicative activity, which in consequence creates difficulty with comprehending speech accompanied by noise. Obviously difficulty in speech comprehension leads to lower speech intelligibility scores. The idea behind this study is to check if a relationship between speech intelligibility scores and noise annoyance exists. A psychoacoustic experiment was designed to test how different types of noise impaired speech intelligibility. Nine noises were used to obtain the speech reception threshold (SRT), defined as the speech to noise ratio (SNR) corresponding to 50% correct responses. To get speech intelligibility scores, the Polish sentence matrix test (PSMT) was applied. The participants’ task was to recreate a whole sentence which they had heard accompanied by noise. In addition, after each sentence, the participants were asked to assess (on a scale from 0-10) how difficult it was to comprehend the sentence heard. The difficulty with comprehending speech accompanied by noise is understood here as annoyance caused by this noise. The results show that the noise annoyance measure recorded during communicative activity is directly related to the speech intelligibility scores: 50% correctly recognized sentences corresponds to the same measure of difficulty with speech comprehension.