Environmental sound perception in individuals with hearing loss: A systematic review

OBJECTIVE: This systematic review aimed to clarify the current status of environmental sound perception in individuals with hearing loss using hearing aids and/or cochlear implants, and to identify effective support methods. METHODS: We systematically reviewed articles on environmental sound perception in individuals with hearing loss published between 1995 and June 22, 2025. Four databases (PubMed, Scopus, Google Scholar, and the Cochrane Library) were searched, and these searches were supplemented by a manual review of a prior systematic review on environmental sound perception in cochlear implant users and its reference list. Using PICOS criteria, we organized the evidence regarding the current status of environmental sound perception, associated factors, and the effects of interventions aimed at improvement. Risk of bias and levels of evidence were also assessed. RESULTS: Of 2609 records, 15 peer-reviewed original articles were included. In environmental sound identification tasks, individuals with hearing loss generally showed poorer performance than normal-hearing listeners; however, performance among individuals with hearing loss varied widely across studies depending on task format, the presence of contextual scenes, scoring methods, and device-related performance differences. Associations with background factors showed consistent correlations with speech perception performance and cognitive function, whereas findings for age and hearing thresholds were inconsistent. Acoustic characteristics, particularly frequency and temporal information, as well as categorical characteristics such as human sounds and non-verbal human vocalizations also influenced performance. Improvements in environmental sound identification associated with hearing aids and cochlear implant use alone were modest, whereas a training-based intervention study reported improved performance in environmental sound identification. CONCLUSIONS: This systematic review indicates that environmental sound perception in individuals with hearing loss is generally poorer than that in normal-hearing listeners, although these difficulties may be restricted to specific stages of perception. Environmental sound perception is also influenced by individual background factors, device-related differences, and the acoustic and categorical characteristics of environmental sounds. Preliminary evidence from a single study suggests that training may improve environmental sound identification; however, further controlled studies are needed to confirm its efficacy and generalizability. These findings provide foundational knowledge to guide auditory rehabilitation.