Spectrotemporal Features in Identifying Environmental Sounds: A Scoping Review

OBJECTIVE: Environmental sounds are important in our day-to-day auditory experiences. Acoustic properties of sounds help listeners identify and interpret them. Understanding the spectrotemporal features of the environmental sounds is valuable for designing auditory devices and interventions, especially for individuals with hearing impairments. This article aimed to understand the role of spectrotemporal information in the perception of environmental sounds. DESIGN: A literature search was carried out using five electronic databases, including Cochrane Library, Scopus, Web of Science, PubMed, and CINAHL. Key words broadly representing environmental sounds and spectrotemporal features were used. A quality assessment tool for systematic reviews and meta-analyses (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), developed by the National Institutes of Health (Study Quality Assessment Tools), was used for this process. RESULTS: A total of 14 studies that explored the role of either temporal or spectral features or both in environmental sound perception were identified. The combination of spectral measures (such as harmonicity, spectral centroid, spectral velocity, and resolution) and temporal measures (such as duration, envelope, rhythm, and onset time) provides the auditory system with the necessary information to infer the physical properties and actions of sound-producing sources. The most informative frequency range for environmental sound identification was found to be 1200-2400 Hz, comparable to the critical frequency regions of speech. CONCLUSIONS: This scoping review indicates that spectrotemporal features of environmental sounds play a significant role in auditory perception. The review also reveals substantial heterogeneity in study methodologies, thereby making it difficult to generalize. However, the specific features identified in this review may be useful for aural rehabilitation in individuals with hearing disorders.