Effects of Speaking Rate on Breathing and Voice Behavior

Laura Lund Kuhlmann,Jenny Iwarsson

doi:10.1016/j.jvoice.2021.09.005

Laura Lund Kuhlmann, Jenny Iwarsson

Open Access

https://doi.org/10.1016/j.jvoice.2021.09.005

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Abstract

The objective of this study was to investigate the effects of speaking rate (habitual and fast) and speech task (reading and spontaneous speech) on seven dependent variables: Breath group size (in syllables), Breath group duration (in seconds), Lung volume at breath group initiation, Lung volume at breath group termination, Lung volume excursion for each breath group (in % vital capacity), Lung volume excursion per syllable (in % vital capacity) and mean speaking Fundamental frequency (fO). Ten women and seven men were included as subjects. Lung volume and breathing behaviors were measured by respiratory inductance plethysmography and fO was measured from audio recordings by the Praat software. Statistical significance was tested by analysis of variance. For both reading and spontaneous speech, the group increased mean breath group size and breath group duration significantly in the fast speaking rate condition. The group significantly decreased lung volume excursion per syllable in fast speech. Females also showed a significant increase of fO in fast speech. The lung volume levels for initiation and termination of breath groups, as well as lung volume excursions in % vital capacity, showed great individual variations and no significant effects of rate. Significant effects of speech task were found for breath group size and lung volume excursion per syllable, where reading induced more syllables produced per breath group and less % VC spend per syllable as compared to spontaneous speech. Interaction effects showed that the increases in breath group size and breath group duration associated with fast rate were significantly larger in reading than in spontaneous speech. Our data from 17 vocally untrained, healthy subjects showed great individual variations but still significant group effects regarding increased speaking rate, where the subjects seemed to spend less air per syllable and inhaled less often as a consequence of greater breath group sizes in fast speech. Subjects showed greater changes in breath group patterns as a consequence of fast speech in reading than in spontaneous speech, indicating that effects of speaking rate are dependent on the speech task.

Highlights

Speaking rate seems to be a parameter of relevance to voice function
It has been suggested that a fast habitual speaking rate is associated with increased risk of developing functional voice disorders due to vocally traumatic behaviors such as hyperfunctional voice use or glottal attacks[1] and clinical experiences from voice therapy suggest that voice quality and pitch can change with a change in speaking rate.[1,2]
Previous research has found that phonation at low lung volume levels induces a lower transglottal airflow and a more hyperfunctional type of phonation.[3−5] A mechanical linkage between lung volume and the voice source in terms of a tracheal pull has been described as a possible explanation to such phonatory effects.[3,5−7] speaking lung volume has been shown to affect fundamental frequency and sound pressure level (SPL), showing that speaking at higher lung volume levels is associated with increased speaking fO and SPL.[4,5,7,8]

Summary

Introduction

One possible hypothesis regarding the physiological coupling between speaking rate and voice is that a fast rate involves higher articulatory demands, leading to increased laryngeal tension.[1] Previous research has found increases in both speaking fundamental frequency (fO) and sound pressure level (SPL) of repeated sentences or syllables with increased speaking rate, findings that might be explained by a general increase in muscle tone during fast speech.[1,2]. Another possible coupling between speaking rate and voice is that speaking rate affects speech breathing behavior in terms of e.g. breath group size and speaking lung volumes. Previous research has found that phonation at low lung volume levels induces a lower transglottal airflow and a more hyperfunctional type of phonation.[3−5] A mechanical linkage between lung volume and the voice source in terms of a tracheal pull has been described as a possible explanation to such phonatory effects.[3,5−7] speaking lung volume has been shown to affect fundamental frequency (fO) and sound pressure level (SPL), showing that speaking at higher lung volume levels is associated with increased speaking fO and SPL.[4,5,7,8] This might be a result of the increased subglottal pressure (Ps) associated with the elastic recoil forces of the system at high lung volume levels in untrained voice users.[7,8]

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