Perceptual and acoustic impacts of aberrant properties of electrolaryngeal speech

Advanced laryngeal cancer is often treated by surgical removal of the larynx (laryngectomy) thus rendering patients unable to produce normal voice and speech. Laryngectomy patients must rely on an alternative means of producing voice and speech, with the most common method being the use of an electrolarynx (EL). The EL is a small, hand-held, electromechanical device that acoustically excites the vocal tract when held against the neck or at the lips. While the EL provides a serviceable means of communication, the resulting speech has several shortcomings in terms of both intelligibility and speech quality. Previous studies have identified and tried to correct different single selected acoustic properties associated with the abnormal quality of EL speech, but with only limited success. There remains uncertainty about: 1) which components of the EL speech acoustic signal are contributing most to its abnormal quality and 2) what kinds of acoustic enhancements would be most effective in improving the quality of EL speech. Using a combination of listening experiments, acoustic analysis and acoustic modeling, this thesis investigated the perceptual and acoustic impacts of several aberrant properties of EL speech, with the overall goal of using the results to direct future EL speech improvement efforts. Perceptual experiments conducted by having 10 listeners judge the naturalness of differently enhanced versions of EL speech demonstrated that adding pitch information would produce the most benefit. Removing the EL self-noise and correcting for a lack of low frequency energy would also improve EL speech, but to a lesser extent. However,

Department dc:contributor.department

Harvard University--MIT Division of Health Sciences and Technology.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2003

Author dc:creator

• Meltzner, Geoffrey S. (Geoffrey Seth), 1973-

Advisor dc:contributor.advisor

• Robert E. Hillman and Kenneth N. Stevens.

• Harvard University--MIT Division of Health Sciences and Technology.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/29760

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/29760