The Perception and Use of High-Frequency Speech Energy: Clinical and Research Implications

Abstract

Purpose High-frequency speech energy (above approximately 4–5 kHz) is garnering substantial research attention. This review surveys recent evidence surrounding the presence and use of perceptual information in the high-frequency region. Additionally, clinical and research applications relevant to speech, language, and hearing professionals are discussed. Method Five databases were used during the search (Medline, CINAHL, WorldCat, ERIC, and Google Scholar). Criteria for study inclusion included (a) peer review, (b) utilization of high-frequency energy (above approximately 4 kHz) during the experimental tasks, and (c) were published from 2014 to present. Fifty-seven articles were included for review, and after further inspection, 13 met the inclusion criteria and were retained. Results Thirteen peer-reviewed studies provided evidence to support the supposition that important and useable acoustic cues exist in the high-frequency portion of the speech spectrum. Conclusions Considering the evidence discussed in this document, it is apparent that the high-frequency region contains additional perceptual cues than currently assumed. Specifically, acoustic cues regarding segmental information (vowel and consonant identification), individual speaker identity, and speaker sex are available for use by human listeners and automated machine recognition systems. Additionally, the high-frequency speech region may reduce listening effort and improve speech recognition in noisy listening conditions, particularly when the speech and noise are spatially separated. Therefore, clinicians and researchers should be aware of this information, which can inform clinical practice when fitting amplification devices for various clinical populations and experimental research for speech and hearing scientists.