Speech intelligibility and naturalness are distinct perceptual dimensions that do not track each other
Evidence
Two parameters are found to be important by those who work on speech: the “intelligibility” and the “quality” or “naturalness” of the speech. Both reflect human perception of the speech itself, and while they are most directly measured subjectively with panels of human listeners, research is being carried out to make equivalent objective measurements of these because of the problems of setting up listening experiments and the inherent interand intralistener variability. The relationship between intelligibility and naturalness is not fully understood. Speech that is unintelligible would usually be judged as being unnatural. However, muffled, fast or mumbling speech is natural but less intelligible, and speech that is highly intelligible may or may not be unnatural. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2398
Categorization
- DEFINE: Separates intelligibility from naturalness and shows the two are not inverse measures of each other.
- QUESTION: If the intelligibility-naturalness relationship is not fully understood, what objective measure could capture both?
- corroborated: 3 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2398
- XREF: connects to: Prescriptive rule choice hardly affects speech intelligibility outcomes; Speech intelligibility alone cannot capture loss of speaker identity in codecs — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 2437; Deficits in any perceptual dimension impair everyday communication (+2 more)