Mahya Sharifinik - Department of Audiology, Rehabilitation Research Center, Iran University of Medical Sciences, Tehran, Iran.
Mohsen Ahadi - Department of Audiology, Rehabilitation Research Center, Iran University of Medical Sciences, Tehran, Iran.
Vida Rahimi - Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran.

Objectives: Bilingualism and multilingualism are on the rise in many parts of the world. Learning and using other languages, in addition to the expected impact on language domains, can affect non-linguistic fields such as attention, working memory, cognitive control, and auditory processing. The objective of this study was a comprehensive review of the bilingual advantage and disadvantages with emphasis on its effect on the cognitive process and its relationship with auditory processing. Methods: A total of ۱۳۳ articles were initially found in this field. According to the inclusion and exclusion criteria of the review, ۸۴ related articles were entered into this study. Then we searched articles published ۲۰۰۵-۲۰۲۰ in Science Direct, Scopus, Google Scholar, and PubMed databases. Keyword and MeSH terms were used in the search process: “bilingualism”, “cognitive process”, “auditory process”, and “auditory attention”.  Results: Studies showed that bilingualism not only has advantages in the linguistic domain but also affects the cognitive domain, especially auditory attention, auditory memory capacity, and inhibitory control. Also, it has a protective effect against cognitive decline in aging. Structural changes in the brain in bilinguals support these effects. Most studies reported that enhanced attentional requests of bilingual exchange amplify connectivity among cognitive functions like attentional rein and auditory processing. These effects create more constancy in the auditory evoked response in bilinguals. Discussion: Learning foreign languages could provoke the autonomic sound processing capability of the auditory organ and make it highly efficient in challenging listening conditions. It also affects other cognitive processes such as auditory memory. However, a comprehensive framework for this relationship is still unknown, and further research is needed, especially to support neurophysiological evidence.

Bilingual, Auditory processing, Auditory attention, Memory, Alzheimer's disease