Quantifying the benefits of sentence repetition on the intelligibility of speech in continuous and fluctuating noises

Abstract

Good verbal communication is essential to ensure safety in the workplace and social participation during daily activities. In many situations, speech comprehension is difficult due to hearing problems, the presence of noise, or other factors. As a result, listeners must often ask the speaker to repeat what was said in order to understand the complete message. However, there has been little research describing the exact benefits of this commonly used strategy. This study reports original data quantifying the effect of sentence repetition on speech intelligibility as a function of signal-to-noise ratio and noise type. Speech intelligibility data were collected using 18 normal-hearing individuals. The speech material consisted of the sentences from the Hearing In Noise Test (HINT) presented in modulated and unmodulated noises. Results show that repeating a sentence decreases the speech reception threshold (SRT), as expected, but also increases the slope of the intelligibility function. Repetition was also found to be more beneficial in modulated noises (decrease in SRT by 3.2 to 5.4 dB) than in the unmodulated noise (decrease in SRT by 2.0 dB). The findings of this study could be useful in a wider context to develop predictive tools to assess speech comprehension under various conditions.