Speech without lips: an acoustic and articulatory study

Abstract

This paper studies the use of a lip retractor as a potential technique for phonetic studies involving perturbation. This device is currently used by participants of the internet sensation, the so-called ‘’no lips’’ or ‘‘mouth guard’’ challenge. Wearing the device restricts the use of the lips during speech. We present acoustic and articulatory data from four speakers of British English. Accelerometer data is used to assess the dynamics of the jaw and ultrasound tongue imaging gives us insights into potential compensation strategies, specifically for the /u/ (GOOSE) vowel. Ultrasound data revealed that three speakers showed signs of tongue retraction for perturbed /u/, which was not reflected in the corresponding acoustic data. This study highlights the limitations of a purely acoustic analysis of the effects of perturbation on speech. Despite certain limitations, we conclude that the use of the lip retractor is a promising technique for future lip perturbation studies.