temporal processing

Perception of speech in noise (SIN) is based on the accurate extraction of spectral and temporal cues. Disruption of this process can reduce the productivity of the spectral and temporal features of the target stimulus and speech recognition in noise. Auditory processing disorder is one of the main challenges of people with stroke, which leads to social, mental, and even physical failures. This study aimed to investigate the spectral and temporal processing abilities of people with stroke compared to healthy peers.

In this study, participants were 15 patients with stroke referred to the neurology clinic of Imam Khomeini Hospital and 30 healthy people aged 20–60 years. Spectral Modulation Detection Test (SMDT), Pitch Pattern Sequencing Test (PPST), Random Gap Detection Test (RGDT) and QuickSIN tests were performed for all participants. The mean scores of the two groups were compared.

Patients with stroke had poorer performance in SMDT, PPST, RGDT and QuickSIN tests (p<0.001) compared to healthy subjects. The results showed that there was a significant correlation between SIN test with temporal and spectral processing in the normal group, but the correlation pattern was different in people with stroke. The scores of all the tests were not significantly different between the right and left ears.

The results showed that people with stroke have poorer performance in all tests compared to normal people and have more problems in speech perception in challenging areas.

Many aspects and features of auditory system can be improved by musical training. This study aimed to investigate the effects of a stringed musical instrument playing course on temporal resolution and temporal fine structure (TFS) processing.

This analytical cross-sectional study was conducted on 44 normal-hearing adults aged 20–40 years divided to two groups. The first group included 22 stringed musical instruments players (13 males) with at least three years of experience, and the second group were 22 non- players (13 males). The random gap detection test (RGDT) was used to measure temporal resolution aspect of hearing. For TFS processing, latest version of temporal fine structure-adaptive frequency (TFS-AF) test was used.

The TFS-AF results showed no statistically significant difference between groups in different interaural phase differences (IPDs). The RGDT results showed significant differences between groups at 500, 1000 and 2000 Hz, but not at 4000 Hz. Spearman correlation test results showed no statistically significant correlation between the results of TFS-AF and RGDT.

Musical training has no effect on TFS processing but considerably enhances gap detection ability. Their underlying mechanisms for TFS processing and gap detection are different.

The majority of the world’s population is bilingual. Bilingualism is a form of sensory enrichment that translates to gains in cognitive abilities; these cognitive gains in attention and memory are known to modulate subcortical processing of auditory stimuli. Second language acquisition has a broad impact on various psychological, cognitive, memory, and linguistic processes. Central auditory processing (CAP) is the perceptual processing of auditory information. Due to its importance in bilingu alism, this study aimed to review the CAP of bilinguals.

The CAP was studied in three areas: dichotic listening, temporal processing, and speech in noise perception. Regarding dichotic listening, studies have shown that bilinguals have better performance in staggered spondaic word (SSW) test, consonant-vowel dichotic test, dichotic digits test (DDT), and disyllable dichotic test than monolinguals, although similar results have also been reported in SSW and DDT. Regarding temporal processing, the results of bilinguals do not differ from those of monolinguals, although in some cases, it is better in bilinguals. Regarding speech in noise perception, the results between bilinguals and monolinguals are varied depending on the amount of linguistic information available in the stimuli.

Bilingualism has a positive effect on dichotic processing, no effect on temporal processing, and varied effect on speech in noise perception. Bilinguals have poor performance using meaningful speech and better performance using meaningless speech.

One of the consequences of aging is temporal processing impairment and reduced neural synchronization, which reduces speech comprehension in challenging situations such as noisy and reflective environments. This study aimed to develop a novel temporal processing-based auditory training program for the senior users of hearing aids.

The program was designed based on different aspects of temporal processing and consists of multiple duty including: 1) detect the number of stimuli, 2) detect the pitch of the stimuli, 3) detect the duration pattern, 4) detect the number of nonsense speech stimuli in noise, and 5) detect the gap in noise. The program consists of 36 sessions (1800 exercises) and one or more features of temporal processing are challenged in all sections.

Content validity ratio, content validity index and impact score were used for validation. The results showed acceptable validity.

Since training exercises can improve the physiological representation of sounds by changing hearing maps and temporal decoding, and these changes lead to improved perception, therefore, the auditory rehabilitation program for the seniors with emphasis on the temporal features of speech, was designed and developed. So it is hoped that with the implementation of the rehabilitation program in the seniors with hearing loss, the effects of age related hearing loss, including depression and social isolation, will be reduced to some extent.