Johan Sundberg 1 , Laura Enflo 1 , Friedemann Pabst 2

1 KTH, Speech Music Hearing, Stockholm

2 Krankenhaus Dresden-Friedrichstadt, , Dresden

Phonation threshold pressures (PTP) have been commonly used for obtaining a quantitative measure of vocal fold motility. However, as these measures are quite low, it is typically difficult to obtain accurate data. As the amplitude of an electroglottograph (EGG) signal decreases substantially at the loss of vocal fold contact, it is mostly easy to determine the collision threshold pressure (CTP) from an EGG signal. In an earlier investigation (Enflo & Sundberg, forthcoming) we measured CTP and compared it with PTP. Results showed that CTP was on average about 4 cm H₂O higher than PTP.

The PTP has been found to increase during vocal fatigue. In the present study we compare PTP and CTP before and after vocal fatigue induced in singer and non-singer voices by a vocal loading procedure previously used by Pabst. The subjects repeated the vowel sequence /a,e,i,o,u/ at an SPL of at least 80 dB @ 0.3 m for 20 min. During the measurements the subjects produced a diminuendo repeating the syllable /pa/. Oral pressure during the /p/ occlusion was used as a measure of subglottal pressure. The accuracy of the measurement of both thresholds will be compared and discussed.

Christina SHEWELL 1,2

1 University College London, The Division of Psychology and Language Sciences, London

2 Southmead Hospital, Speech and Language Therapy, Bristol

Diane Hazlett 1 , Orla Duffy 2 , Anne Moorhead 1

1 University of Ulster, School of Communication, Newtownabbey

2 University of Ulster, School of Health Sciences, Newtownabbey

leo meulenbroek 1

1 Hogeschool van Arnhem/Nijmegen, education, Arnhem