Sex differences in perceived speech intelligibility in patients with facial nerve palsy

Facial nerve palsy (FNP) affects physical and social function, including speech. There exists discrepancy between professional and patient perception of appearance following FNP; however, speech differences remain unknown. We aimed to compare ratings of speech intelligibility by different listeners.

Patients were identified through the Sydney Facial Nerve Service. FNP related scoring was obtained using the Sunnybrook Facial Grading System, Sydney Facial Grading Score, Facial Disability Index, and Speech Handicap Index. Intelligibility was scored by a speech-language pathologist, member of the public, and patient using a standardised passage. FNP scoring and intelligibility were compared using interclass coefficients (ICC).

Forty patients were recruited (females = 20). There was no difference in FNP scoring, nor between the frequency or types of phonemic errors. Observers' rating of intelligibility had an ICC of 0.807, compared with 0.266 and 0.344 for patients compared to the member of the public and speech-language pathologist respectively. Observers rated males and females intelligibility similar (p > 0.05), but females rated their intelligibility lower than males (74.5 ± 12.8 vs. 82.5 ± 8.4, p = 0.025).

Patients, particularly females, perceive their speech to be less intelligible than observers. Clinicians should be aware of this discrepancy, which does not correlate with physical function.