Individuals who have had a laryngectomy (IWL) and who use an alternative form of voice (i.e., tracheosophageal [TE], esophageal [ES], electrolaryngeal [EL]) have reduced speech intelligibility. Much research has been done identifying factors that may contribute to the reductions in speech intelligibility (e.g., acoustic, aerodynamic, kinematic) but these studies have focused on the speaker and not the listener. Other areas of communication disorders have recognized the importance of the listener when discussing speech intelligibility. For example, increased intelligibility has been reported for normal listeners who were familiarized with a specific form of motor speech disorder (e.g., Liss et al, 2002) or who were provided visual cues in addition to the speech signal (e.g., Hustad & Garcia, 2005). Other than the listener's role on speech intelligibility, the role of visual information and increased speech intelligibility has been well documented for normal and hearing-impaired listeners (e.g., Brenatari & Wolk, 1986; Walden, Busacco, & Montgomery, 1993). However, few studies exist that look at the effects of visual information on speech intelligibility with disordered speakers. It is reasonable to suspect that listeners may behave differently with a disordered speaker than a normal speaker. For instance, listeners may be distracted by a stoma, altered anatomy, or other extraneous movements inherent to alaryngeal speech production (e.g., digital occlusion with TE speech, injection of air into the esophagus for ES, the presence of a mechanical device with EL speech). Furthermore, the listener may be receiving incongruent auditory and visual information (i.e., the McGurk Effect; McGurk & McDonald) because of these changes in anatomy or speech patterns. The purpose of this experiment will be to investigate the role of visual information on normal listeners when presented with alaryngeal speech. This will be accomplished by tracking the eye-gaze behaviors of normal listeners when presented with both normal, laryngeal and alaryngeal speech.
Specific aims (SA) of the project are to: 1) determine normal listener eye-gaze behavior during conversation with a normal, laryngeal speaker (Experiment 1), 2) determine normal listener eye-gaze behavior during conversation with proficient, high-intelligibility alaryngeal speakers (Experiment 1), and 3) determine normal listener eye-gaze behavior during conversation with low/moderate-intelligibility alaryngeal speakers (Experiment 2). Future work involving eye-gaze tracking behavior and laryngeal cancer will: 1) lead to a more complete understanding of the decreases in speech intelligibility experienced by IWL, 2) lead to the development of therapeutic approaches that target increased alaryngeal speech intelligibility, and 3) provide a more complete understanding of potential listener reactions or behaviors that IWL may experience. ? ? ?
| Evitts, Paul; Gallop, Robert (2011) Objective eye-gaze behaviour during face-to-face communication with proficient alaryngeal speakers: a preliminary study. Int J Lang Commun Disord 46:535-49 |
