Measurement of Voice Onset Time in Maxillectomy Patients

Mariko Hattori,Hisashi Taniguchi,Yuka I Sumita

doi:10.1155/2014/925707

Mariko Hattori, Hisashi Taniguchi + Show 1 more

Open Access

https://doi.org/10.1155/2014/925707

Copy DOI

Journal: TheScientificWorldJournal	Publication Date: Jan 1, 2014
Citations: 16	License type: CC BY 3.0

Affiliation: Tokyo Medical and Dental University

Abstract

Objective speech evaluation using acoustic measurement is needed for the proper rehabilitation of maxillectomy patients. For digital evaluation of consonants, measurement of voice onset time is one option. However, voice onset time has not been measured in maxillectomy patients as their consonant sound spectra exhibit unique characteristics that make the measurement of voice onset time challenging. In this study, we established criteria for measuring voice onset time in maxillectomy patients for objective speech evaluation. We examined voice onset time for /ka/ and /ta/ in 13 maxillectomy patients by calculating the number of valid measurements of voice onset time out of three trials for each syllable. Wilcoxon's signed rank test showed that voice onset time measurements were more successful for /ka/ and /ta/ when a prosthesis was used (Z = −2.232, P = 0.026 and Z = −2.401, P = 0.016, resp.) than when a prosthesis was not used. These results indicate a prosthesis affected voice onset measurement in these patients. Although more research in this area is needed, measurement of voice onset time has the potential to be used to evaluate consonant production in maxillectomy patients wearing a prosthesis.

Highlights

Maxillectomy patients often have speech impairments caused by communication between the nasal and oral cavities and a missing palate and teeth, which are important for articulation
The number of successful Voice onset time (VOT) measurements was larger with a prosthesis
VOT measurements were invalid in many of the maxillectomy patients when not wearing a maxillofacial prosthesis, indicating that their production of plosives such as /ka/ and /ta/ was impaired by maxillary deficiency

Summary

Introduction

Maxillectomy patients often have speech impairments caused by communication between the nasal and oral cavities and a missing palate and teeth, which are important for articulation. Speech rehabilitation includes fitting with a maxillofacial prosthesis and speech evaluation [1, 2]. The intelligibility of these patients is typically evaluated by a listening test [1, 2], but objective evaluation by acoustic analysis is needed [3, 4]. Acoustic analysis adds important objective and quantitative information to the clinical speech evaluation. An automatic speech test using computerized speech recognition has been used, this computer-based evaluation was found to be appropriate only for overall speech assessment in maxillectomy patients, not for detailed consonant assessments [6]

Objectives

Methods

Results