Envelope-based inter-aural time difference localization training to improve speech-in-noise perception in the elderly

Abstract

Background: Many elderly individuals complain of difficulty in understanding speech in noise despite having normal hearing thresholds. According to previous studies, auditory training leads to improvement in speech-in-noise perception, but these studies did not consider the etiology, so their results cannot be generalized. The present study aimed at investigating the effectiveness of envelopebased interaural time difference (ITD ENV) localization training on improving ITD threshold and speech-in-noise perception. Methods: Thirty-two elderly males aged 55 to 65 years with clinically diagnosed normal hearing at 250-2000 Hertz, who suffered from speech-in-noise perception difficulty participated in this study. These individuals were randomly divided into training and control groups: 16 elderlies in the experimental group received envelope-based interaural time difference localization training in 9 sessions, but 16 matched elderlies in the control group did not receive any training. The ITD ENV threshold and spatial word recognition score (WRS) in noise were analyzed before and after the localization training. Results: Findings demonstrated that following the training program, the interaural time difference envelope threshold and spatial word recognition score (WRS) in noise were improved significantly in the experimental group (p≤ 0.001). Moreover, a significant difference was detected in interaural time difference envelope threshold and spatial word recognition score (WRS) in noise (p≤ 0.001) before and after the training in the experimental group. Conclusion: The results of the present study revealed the effectiveness of envelope- based interaural time difference localization training in localization ability and speech in noise perception in the elderlies with normal hearing up to 2000 Hz who suffered from speech-in-noise perception difficulty.

Auditory Spatial Training-Induced Changes in the Release of Informational Masking in Older Adults

“…This suggests the incidence of neural plasticity in the intervention group, which concurs with the study's main hypothesis and the results from some previous studies conducted on older adults [22,[32][33][34]. Given the lack of similar studies and since only a few studies have been conducted on spatial auditory training, studies with similar practical concepts (all conducted to improve speech in noise perception) conducted on older age groups were selected [22,31,32,[34][35][36]. The most important point extracted from these studies was that neural plasticity occurs in older adults through short-term training.…”

The Correlation Analysis Between the Spatial Hearing Questionnaire (SHQ) and the Psychophysical Measurement of Spatial Hearing

“…For this purpose, the Pearson test was used to assess the relationship between P-SHQ score and the score of the spatial word in noise test among three groups. For the interpretation of these results, it should be noted that the relationship between the objective and self-assessment tests depends on their validity [7,13]. In this study, the tests with high levels of reliability and validity were selected [12].…”

“…Various behavioral (psychophysical) tests have been introduced for the assessment of spatial hearing including the Masking Level Difference (MLD), the Dichotic Digits test (DDT), the minimum audible angle (MAA), the Listening in Specialized Noise test (LiSN), and the spatial word recognition score [6][7][8]. On the other hand, various self-report assessment tools have been introduced for investigating the spatial hearing disabilities including the Spatial Hearing Questionnaire (SHQ) and the Speech, Spatial and Qualities of Hearing Scale (SSQ) [9][10][11].…”

“…The words are presented in noise with signal to noise ratio of 0 dB [2]. In the study of Zamiri et al and Delphi et al [2,13], this test was used to measure the psycho-physical aspect of spatial hearing. In the present study, the scores of SHQ and spatial word in noise test were compared among three groups of participants: (a) normal-hearing subjects, (b) subjects with mild hearing loss, and (c) subjects with moderate hearing loss.…”

The effects of auditory spatial training on informational masking release in elderly listeners: a study protocol for a randomized clinical trial

“…In this formula, the studied variable is the extent of informational masking changes before and after the intervention. There is no previous study, which was used the same training as this study proposes; therefore, we considered the study of Delphi et al which was on a group of elderly individuals 44 . In her study the mean and standard deviation of the improvement in the main variable were 37.5 and 25.17 in the experimental group and 25.17 and 18.15 in the control group, respectively.…”