Relationship between phoneme-level spectral acoustics and speech intelligibility in healthy speech: a systematic review

This study aims to systematically review original articles investigating the link between spectral acoustic measures in healthy talkers and perceived speech intelligibility, according PRISMA guidelines. Twenty-two studies were retained. Eighteen papers investigated vowel acoustics, one studied glides eight consonants, mostly sibilants. Various intelligibility estimates used. The following shown be linked sub-lexical ratings: for vowels, steady-state F1 F2 measures, range, [i]-[U] difference, F0-F1 F1-F2 differences [è-A] [q-è], space area, mean amount of formant movement, vector length change measure; centroid energy peak [s]-sound, as well offset frequency vowels preceding [t] [d].To conclude, is highly variable even adult speakers, a better understanding imprecisions spontaneous will provide more realistic baseline investigation disordered speech. To date, no measure able predict large extent. There still extensive research carried out identify relevant combinations that could account variations (e.g. consonant reductions) gather normative data from number speakers. end, speech-related terms comprehensibility, severity) need clearly defined methodologies described sufficient details allow replication, cross-comparisons/meta-analyses pooling data. .