Hostname: page-component-77c78cf97d-sp94z Total loading time: 0 Render date: 2026-04-24T06:47:21.938Z Has data issue: false hasContentIssue false

Electroglottogram approximate entropy: a novel single parameter for objective voice assessment

Published online by Cambridge University Press:  04 February 2010

C M Douglas*
Affiliation:
Department of Head and Neck Surgery, Christie Hospital NHS Trust, Manchester, UK
C Moore
Affiliation:
Department of Medical Physics, Christie Hospital NHS Trust, Manchester, UK
K Manickam
Affiliation:
Department of Medical Physics, Christie Hospital NHS Trust, Manchester, UK
L Lee
Affiliation:
Department of Clinical Oncology, Christie Hospital NHS Trust, Manchester, UK
A Sykes
Affiliation:
Department of Clinical Oncology, Christie Hospital NHS Trust, Manchester, UK
A Carr
Affiliation:
Department of Speech and Language Therapy, Christie Hospital NHS Trust, Manchester, UK
S Jones
Affiliation:
Department of Speech and Language therapy, Wythenshawe Hospital, South Manchester University NHS trust, Manchester, UK
J Jones
Affiliation:
Department of Speech and Language Therapy, Christie Hospital NHS Trust, Manchester, UK
R Swindell
Affiliation:
Department of Medical Statistics, Christie Hospital NHS Trust, Manchester, UK
J J Homer
Affiliation:
Department of Head and Neck Surgery, Christie Hospital NHS Trust, Manchester, UK
N Slevin
Affiliation:
Department of Clinical Oncology, Christie Hospital NHS Trust, Manchester, UK
*
Address for correspondence: Dr C Douglas, Department of Head and Neck Surgery, Christie Hospital NHS Trust, Manchester M20 4BX, UK. Fax: 01614468593 E-mail: cat1979@doctors.org.uk

Abstract

Background:

The electroglottogram approximate entropy value is a numerical variable which gives an overall measure of voice quality. It is derived by analysing the complexity of the electroglottogram waveform using regulatory statistics.

Aims:

(1) To use electroglottogram approximate entropy to measure voice quality in patients with glottic pathology and in normal subjects, to ascertain whether this parameter can distinguish between pathological and normal voices. (2) To ascertain whether electroglottogram approximate entropy can measure voice change over time within individual subjects. (3) To determine any correlation between electroglottogram approximate entropy and the grade–roughness–breathiness–asthenia–strain scale.

Methods:

One hundred and forty-one normal volunteers were recruited to characterise electroglottogram approximate entropy in the normal voice. One hundred and eighty-six patients with glottic squamous cell carcinoma underwent electroglottogram approximate entropy measurement prior to radiotherapy and then three to six months and one year after treatment. Subjects’ voices were categorised by a speech therapist using the grade–roughness–breathiness–asthenia–strain scale.

Results:

The mean electroglottogram approximate entropy of the normal volunteers was 0.302 (range 0.05–0.42). The mean electroglottogram approximate entropy of the glottic squamous cell carcinoma patients was significantly lower prior to treatment, at 0.227 (range 0.001–0.397; p < 0.0005), but improved after radiotherapy to 0.277 at three to six months and 0.282 at one year. Electroglottogram approximate entropy results correlated significantly with grade–roughness–breathiness–asthenia–strain scale results.

Conclusion:

Electroglottogram approximate entropy can be used to assess change in voice quality resulting from glottic morphological abnormality. Electroglottogram approximate entropy values improve as voice quality improves after treatment. Electroglottogram approximate entropy values correlate significantly with grade–roughness–breathiness–asthenia–strain scale results.

Information

Type
Main Articles
Copyright
Copyright © JLO (1984) Limited 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable