The perception of nasal coarticulatory variation in face-masked speech.

This study investigates the impact of wearing a face mask on the production and perception of coarticulatory vowel nasalization. Speakers produced monosyllabic American English words with oral and nasal codas (i.e., CVC and CVN) in face-masked and un-face-masked conditions to a real human interlocutor. The vowel was either tense or lax. Acoustic analyses indicate that speakers produced greater coarticulatory vowel nasality in CVN items when wearing a face mask, particularly, when the vowel is lax, suggesting targeted enhancement of the oral-nasalized contrast in this condition. This enhancement is not observed for tense vowels. In a perception study, participants heard CV syllables excised from the recorded words and performed coda identifications. For lax vowels, listeners were more accurate at identifying the coda in the face-masked condition, indicating that they benefited from the speakers' production adjustments. Overall, the results indicate that speakers adapt their speech in specific contexts when wearing a face mask, and these speaker adjustments have an influence on listeners' abilities to identify words in the speech signal.