Definition and Clinical Implication of Temporal Fine Structure

Abstract

Perception of sound is associated with the use of multiple acoustic cues in the human auditory system. These acoustic cues can be classified by their temporal and spectral properties. Temporal information can be considered as a slowly varying envelope (ENV) superimposed on a more rapid temporal fine structure (TFS). Various sound-processing techniques have been developed to assess the role of acoustic information carried by temporal ENV and TFS information. Previous studies demonstrated that ENV cues are associated with speech recognition in quiet, while TFS cues have a role to melody/pitch perception and listening to speech in a competing background noise. Besides, a number of studies have shown that the relative insensitivity of hearing-impaired subjects to TFS information. Although current technologies used in cochlear implants are not efficient in delivering the TFS cues, new speech processing strategies have been proposed to deliver TFS information. We herein review the cutting edge of TFS related studies and discuss the clinical implication of TFS. Key words: Cochlear implant ㆍ Hearing impairment ㆍ Speech perception ㆍ Temporal envelope ㆍ Temporal fine structure