Phonation stabilisation time as an indicator of voice disorder

There is increasing emphasis on use of connected speech for acoustic analysis of voice disorder, but the differential impact of disorder on initiation, maintenance and termination of phonation has received little attention. This study introduces a new measure of dynamic changes at onset of phonation during connected speech, phonation stabilisation time (PST), and compares this measure with conventional analysis of sustained vowels. Voice samples obtained from the KayPENTAX Disordered Voice Database were analysed (202 females, 128 males) including ‘below threshold’ voices where there was a clinical diagnosis but acoustic parameters for sustained vowels were within the normal range. Female disordered voices showed significantly longer PST duration than normal voices, including those in the ‘below threshold’ group. Overall differences for male voices were also significant. Results suggest that, at least for females, PST measurement from connected speech could provide a more sensitive indicator of disorder than traditional analysis of sustained vowels.