Effects of Auditory Lateralization Training on the Speed Processing and Speech Perception in Noise in the Elderly

Background and Aim: Structural and functional changes in the auditory and cognitive system caused by aging can lead to impaired speech perception and speed processing, especially in the presence of noise. This study aimed to enhance cognitive system performance including speed processing and speech perception by improving the temporal information through lateralization training. Methods: In this interventional study, 36 participants aged 65–75 years with normal hearing, who complained about speech perception in noise, were randomly assigned to the intervention group and the control group. The intervention group received twelve 45-minute sessions of auditory lateralization training. The quick speech-in-noise, words-in-noise, and consonant-vowel-in-noise tests are used as behavioral tests of speech perception in noise at the sentence, word and phoneme levels, respectively. The time-compressed speech test was adopted to measure processing speed. The repeated measures ANOVA was used to analyze the test results before, after, and one month after rehabilitation. Results: A significant decrease in the lateralization errors, and signal-to-noise ratio loss in both the quick speech-in-noise and words-in-noise tests were observed in the intervention group (p<0.001). Moreover, a considerable increase in the word recognition score in the time-compressed speech test and the consonant-vowel in noise test were observed (p<0.001). Coefficient effects were obtained for the quick speech-in-noise test (0.74), the words-in-noise test (0.59) and the consonant-vowel in noise test (0.12). Statistical analyses revealed the stability of the outcomes one month after rehabilitation. Conclusion: Auditory lateralization training can improve the speed of processing and speech perception in noise in the elderly.