The Effect of Tinnitus on Speech Processing: Evidences and Theories

The aim of this review study is to investigate the relationship between tinnitus and speech processing and to explore the possible pathways of involvement in this disorder. For speech processing, all the pathways of the auditory system are involved from the peripheral to the center and cognitive and attention systems. Given the overlapping path that causes the tinnitus and the path to which speech processing comprehends, it seems tinnitus causes speech processing to be disturbed by effect on peripheral to center path of auditory or the presence of tinnitus with effects on attention and cognitive systems can interfere with speech processing. This paper reviews behavioral and electrophysiological evidences in both bottom-up and top-down theories.

In this review, we use from keywords” the tinnitus and Otoacoustic Emissions (OAE), tinnitus and Auditory Brainstem Response (ABR), tinnitus and Middle Latency Response (MLR), tinnitus and waves p300, tinnitus and Mismatch Negativity (MMN) waves, tinnitus and verbal auditory memory, the tinnitus and processing of temporal information, tinnitus and central auditory processing, tinnitus and psychoacoustic evaluation, tinnitus and behavioral auditory evaluation “in the databases Google scholar and Science Direct and Scopus. New and related articles were selected. After reviewing the 76 articles and 6 book and 1 thesis, the review study was extracted.

In explaining the influence of tinnitus on speech comprehension, two theories can be suggested. A theory supports damage to the low levels of brain and brainstem (Bottom -up theory). And another theory, the reduction of speech perception due to the involvement of cognitive and attention systems (Top-down theory). Each of which has its own evidence of support.

In people with tinnitus, behavioral and electrophysiology evidences showed involvement of both speech processing pathways, bottom up and top down