Recognition of stop consonants in babble noise in normal hearing individuals

Abstract

Background and Aim: Speech understanding almost never occurs in silence. Verbal communication often occurs in environments where multiple speakers are talking. In such environments, babbling noise masks speech comprehension. Consonants, in comparison to vowels, are more sensitive to noise masking. Consonants provide most acoustic information needed for comprehending the meaning of the word. Since stop consonants have low intensity, they can be easily masked by noise, and finally tend to lead to speech disorder. This study determines the effect of babble noise on the recognition score of stop consonants.
Methods: This cross-sectional study was performed on 48 participants, males and females in equal number, aged between 19 and 24 years, with normal hearing. In addition to auditory and speech evaluation, recognition of stop consonants in a consonant–vowel–consonant syllable at the presence of babbling noise was tested.
Results: By increasing the noise, the recognition score of stop consonants at the beginning of the syllable was reduced. There was a meaningful difference between the recognition score of stop consonants at the beginning of the word and vowels in the signal-to-noise ratio of 0, -5, and -10 (p=0.000). Besides, the average recognition score of /b/, /d/, /k/, and /ʔ/ was found to be greater than /p/, /t/,/g/, and /q/ (p<0.0005). Gender had no significant effects.
Conclusions: Increased babble noise levels significantly reduce the recognition score of stop consonants, and this reduction is more in some voiced stop consonants as well as some voiceless stop consonants.