Comparison of transducers and intraoral placement options for measuring lingua-palatal contact pressure during speech

Two studies were completed that focused on instrumentation and procedural issues associated with measurement of lingua-palatal contact pressure (LPCP) during speech. In the first experiment, physical features and response characteristics of 2 miniature pressure transducers (Entran EPI-BO and Precision Measurement 60S) were evaluated to identify a transducer suitable for measuring LPCP during speech. The 2 transducers were comparable in terms of physical dimensions and most response characteristics. However, the Entran device was less affected by air temperature fluctuations, making it the more attractive option for speech LPCP measurement. In a second experiment, 3 methods of placing the Entran device in the mouth were compared. The 3 adhesion methods evaluated were (a) taping a transducer to the hard palate, (b) surface mounting on a mold of the palate, and (c) flush mounting on a mold of the palate. Directly taping the transducer to the alveolar ridge was the least acceptable option, as it resulted in changes in other aspects of speech production (consonant duration and centroid frequency of the burst/frication) suggesting that articulation was unduly altered. Direct taping was also rated as least acceptable by the speakers. Surface and flush mounting resulted in fewer changes in speech aerodynamic and acoustic parameters of /t/ and/s/ compared to the tape condition. Listener ratings also indicated less articulatory disturbance in the surface and flush mounting conditions compared to the tape condition. Surface mounting was technically easier than flush mounting and it allows for rapid repositioning of the transducer if needed.