chapter  62
Evaluation of the voice
ByJulian A. McGlashan
Pages 18

Definitions Speech is the expression of or the ability to express thoughts and feelings by articulate sounds.1 The term voice is often used to refer to speech as a whole. However, when used in the context of voice evaluation, it is generally restricted to the acoustic output resulting from the interaction of vocal fold vibration with the vocal tract in vowel production.2, 3 Phonation is a term used to describe the physical and physiological processes of vocal fold vibration in the production of speech sounds.3 Impaired voice production due to abnormal vocal fold vibration is known as dysphonia, while no voice or whispery voice associated with no vocal fold vibration is termed aphonia.4 Hoarseness is a non-specific, general term used to describe any change in voice quality.5