Features of speech signal recognition in conditions of vocal competition with normal hearing and with hearing or speech disorders

We studied the features of speech signals perception in conditions of vocal competition based on gender (male/female voice) in subjects of different ages and status of auditory and speech functions. Psychophysical measurements were carried out while simulating a “speech cocktail” situation by simultaneously pronounced different words by a male and female. The average fundamental voice frequency for the male speaker was 108 ± 5.92 Hz, for the female speaker – 185 ± 12.03 Hz. Both speakers were standard native speakers of the Russian language. Digital recordings of speech signals were equalized in intensity and compounded so that the total test stimulus was a synchronized mixture of words spoken by a male (M) and female (F) voice. Test speech signals were presented through headphones or through a speaker located in front of the auditor at a distance of 50 cm. The indicators of reaction time and the number of correct recognitions of words of the target speaker (M or F) were compared in 4 groups of subjects of different ages and hearing or speech status: adult subjects with normal hearing and speech (n = 35) and with hearing impaired (n = 26); schoolchildren with normotypical development (n = 26) and with speech disorders (n = 25). The results indicated a falling in the ability to segrerate target speech streams under conditions of vocal competition in the subjects with hearing and speech dysfunctions included in the comparative study. Differences in the perception of male and female voices in subjects with hearing loss and with speech problems were obtained. This result may have a biological and social basis. The data have practical significance for the development of a system of auditory and speech training and modern hearing aid technologies.