Vocal effort levels and underlying acoustic phonetic characteristics

Cushing, IR

Abstract

This thesis presents empirical research which investigates diverse vocal effort levels
in anechoic conditions from a large number of British English speakers. Five vocal
effort labels were stipulated: hushed, normal, raised, loud and shout. New results
show similar averages to previous work, but lower standard deviations which are
attributed to the more descriptive vocal effort labels used in this study.
Building on this data, a phonetic investigation into vocal effort was carried out,
taking its inspiration from the natural segmental variation in speech which occurs at
different vocal efforts. Speech was split into voiced and unvoiced components which
allowed for a more phonetically motivated profile of vocal effort. In a bid to mirror
analysis with the speech communication chain of talker to listener, listening tests were
conducted where subjects rated the perceived vocal effort level of isolated words.
Listeners also rated perceived clarity of articulation, taking the assumption that
different degrees of clarity are an inherent feature of different speech levels. Multiple
regression analysis revealed that listeners exploit the voiced-unvoiced distinction in
their perception of vocal effort and clarity of articulation. The resulting validation
equation from the multiple regression model showed that vocal effort levels can be
reliably predicted.

Citation

Cushing, I. Vocal effort levels and underlying acoustic phonetic characteristics. (Thesis). Salford : University of Salford

• Thesis Type: Thesis
• Deposit Date: Oct 3, 2012
• Award Date: Jan 1, 2010