Ramona C. Steiner 1 , Christian T. Herbst 2 , David M. Howard 3

1 University of Salzburg, Department of Linguistics, Salzburg

2 Palacký University Olomouc, Department of Experimental Physics, Olomouc

3 University of York, Department of Electronics, York

The central deficit in unilateral vocal fold pareses (UVFP) is insufficient glottal adduction. Several well-established therapy methods exist, but their efficiency is rarely evaluated objectively. Except for auditory feedback via bone conduction, patients have no means to assess the targeted change in voice quality. In a recent study, electroglottography (EGG) has successfully been used as a real-time biofeedback tool in order to increase the degree of posterior glottal closure in a healthy amateur singer. EGG has also been used recently in an attempt to document voice quality in patients with vocal fold pareses. In this study we investigate whether electroglottographic real-time biofeedback can be used to increase therapy efficiency by enhancing glottal adduction in patients with UVFP.

For this experiment four patients with diagnosed infranuclear UVFP act as subjects. Habitual phonation was documented simultaneously by means of videolaryngoscopy, electroglottography and audio recording when sustaining a vowel at a comfortable pitch. In a therapeutic session, using phonatory exercises (conservative approach), subjects were shown a real-time EGG-waveform (normalized in both amplitude and time) representing one glottal cycle which changes over time. As they followed the instructions of the therapist, they were asked consciously to introduce changes into the shape of the displayed EGG-waveform. Therapy sessions were documented by means of simultaneous recording of acoustic and electroglottographic data. Immediately after therapy session the patients' attempt to apply the potentially improved phonatory behaviour was documented simultaneously by means of videolaryngoscopy, electroglottography and audio recording, again when sustaining a vowel at a comfortable pitch.

First tests showed that the EGG-signal could be detected in a patient with a chronic UVFP, and that he was able to willingly introduce changes into the displayed EGG-waveform during therapy for a sustained vowel. The sessions further explored the effect of training on the ability of patients to change the shape of the EGG-waveform at will which provides support for the use of EGG in therapy.

John Rubin 1 , Ed Blake 2

1 Royal National Throat Nose and Ear Hospital, ENT, London

2 PhysioEd Medical, , London

Coen Honig 1

1 Private teacher, , Den Haag

Alfonso Borragan 1 , Enmanuella Lucchini 2 , Andrea Ricci Maccarini 2 , Giovanni de Rossi 3

1 Centro de Foniatría y Logopedia, , Santander

2 Ospedale “M. Bufalini”, ORL, Cesena

3 Ospedale San Bonifacio di Soave, ORL, Verona