Articulatory Contact Pressure during Bilabial Plosive Production in Esophageal and Tracheoesophageal Speech

Objectives: The present study investigated the articulatory contact pressure during the production of bilabial plosives by esophageal (ES), tracheoesophageal (TE), and laryngeal speakers. Methods: The peak contact pressure (PCP) during bilabial plosive production of /CVCVCVCVCV/ syllable strings of /p/ and /ph/ was obtained from 10 ES, 10 TE, and 10 laryngeal speakers of Cantonese. PCP values were obtained by using a pressure transduction system (Iowa Oral Performance Instrument) during speech production. Results: The results showed that ES speakers exhibited a significantly greater PCP value than TE and laryngeal speakers, as revealed by cheek muscle compression force. In addition, the unaspirated bilabial plosive /p/ was associated with a greater PCP than its aspirated counterpart /ph/. Conclusion: The current findings might support the hypothesis of over-exaggerated speech for better intelligibility among alaryngeal speakers. In addition, the increased oral muscular effort could be associated with a compensatory strategy for maintaining a high intraoral pressure or the unique air intake by ES speakers.