An acoustic measure of lexical stress differentiates aphasia and aphasia plus apraxia of speech after stroke

Marianne K. Vergis, Kirrie J. Ballard, Joseph R. Duffy, Malcolm R. McNeil, Dominique Scholl, Claire Layfield

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Background: Apraxia of Speech (AOS) is partly characterised by impaired production of prosody in words and sentences. Identification of dysprosody is based on perceptual judgements of clinicians, with limited literature on potential quantitative objective measures.Aims: This study investigated whether an acoustic measure quantifying degree of lexical stress contrastiveness in three syllable words, produced in isolation and in a carrier sentence, differentiated individuals with AOS with/without aphasia (AOS), aphasia only (APH), and healthy controls (CTL).Methods & Procedures: Eight individuals with aphasia, nine with AOS plus aphasia and 8 age-matched control participants named pictures of strong-weak and weak-strong polysyllabic words in isolation and in a declarative carrier sentence. Pairwise Variability Indices (PVI) were used to measure the normalised relative vowel duration and peak intensity over the first two syllables of the polysyllabic words.Outcomes & Results: Individuals with aphasia performed similarly to control participants in all conditions. AOS participants demonstrated significantly lower PVI_vowel duration values for words with weak-strong stress produced in the sentence condition only, compared to controls and individuals with aphasia. This was primarily due to disproportionately long vowels in the word-initial weak syllable for AOS participants. There was no difference among groups on PVI_intensity.Conclusions: The finding of reduced lexical stress contrastiveness for weak-strong words in sentences for individuals with mild to moderate-severe AOS is consistent with the perceptual diagnostic feature of equal stress in AOS. Findings provide support for use of the objective PVI_vowel duration measure to help differentiate individuals with AOS (with/without aphasia), from those with aphasia only. Future research is warranted to explore the utility of this acoustic measure, and others, for reliable diagnosis of AOS.

LanguageEnglish
Pages554-575
Number of pages22
JournalAphasiology
Volume28
Issue number5
DOIs
Publication statusPublished - 2014
Externally publishedYes

Fingerprint

Apraxias
Aphasia
speech disorder
stroke
Acoustics
acoustics
Stroke
social isolation
Lexical Stress
Apraxia of Speech
diagnostic

Cite this

Vergis, Marianne K. ; Ballard, Kirrie J. ; Duffy, Joseph R. ; McNeil, Malcolm R. ; Scholl, Dominique ; Layfield, Claire. / An acoustic measure of lexical stress differentiates aphasia and aphasia plus apraxia of speech after stroke. In: Aphasiology. 2014 ; Vol. 28, No. 5. pp. 554-575.
@article{9e6e29d665e34fb0bfe746f1229acdc2,
title = "An acoustic measure of lexical stress differentiates aphasia and aphasia plus apraxia of speech after stroke",
abstract = "Background: Apraxia of Speech (AOS) is partly characterised by impaired production of prosody in words and sentences. Identification of dysprosody is based on perceptual judgements of clinicians, with limited literature on potential quantitative objective measures.Aims: This study investigated whether an acoustic measure quantifying degree of lexical stress contrastiveness in three syllable words, produced in isolation and in a carrier sentence, differentiated individuals with AOS with/without aphasia (AOS), aphasia only (APH), and healthy controls (CTL).Methods & Procedures: Eight individuals with aphasia, nine with AOS plus aphasia and 8 age-matched control participants named pictures of strong-weak and weak-strong polysyllabic words in isolation and in a declarative carrier sentence. Pairwise Variability Indices (PVI) were used to measure the normalised relative vowel duration and peak intensity over the first two syllables of the polysyllabic words.Outcomes & Results: Individuals with aphasia performed similarly to control participants in all conditions. AOS participants demonstrated significantly lower PVI_vowel duration values for words with weak-strong stress produced in the sentence condition only, compared to controls and individuals with aphasia. This was primarily due to disproportionately long vowels in the word-initial weak syllable for AOS participants. There was no difference among groups on PVI_intensity.Conclusions: The finding of reduced lexical stress contrastiveness for weak-strong words in sentences for individuals with mild to moderate-severe AOS is consistent with the perceptual diagnostic feature of equal stress in AOS. Findings provide support for use of the objective PVI_vowel duration measure to help differentiate individuals with AOS (with/without aphasia), from those with aphasia only. Future research is warranted to explore the utility of this acoustic measure, and others, for reliable diagnosis of AOS.",
author = "Vergis, {Marianne K.} and Ballard, {Kirrie J.} and Duffy, {Joseph R.} and McNeil, {Malcolm R.} and Dominique Scholl and Claire Layfield",
year = "2014",
doi = "10.1080/02687038.2014.889275",
language = "English",
volume = "28",
pages = "554--575",
journal = "Aphasiology",
issn = "0268-7038",
publisher = "Psychology Press",
number = "5",

}

An acoustic measure of lexical stress differentiates aphasia and aphasia plus apraxia of speech after stroke. / Vergis, Marianne K.; Ballard, Kirrie J.; Duffy, Joseph R.; McNeil, Malcolm R.; Scholl, Dominique; Layfield, Claire.

In: Aphasiology, Vol. 28, No. 5, 2014, p. 554-575.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - An acoustic measure of lexical stress differentiates aphasia and aphasia plus apraxia of speech after stroke

AU - Vergis, Marianne K.

AU - Ballard, Kirrie J.

AU - Duffy, Joseph R.

AU - McNeil, Malcolm R.

AU - Scholl, Dominique

AU - Layfield, Claire

PY - 2014

Y1 - 2014

N2 - Background: Apraxia of Speech (AOS) is partly characterised by impaired production of prosody in words and sentences. Identification of dysprosody is based on perceptual judgements of clinicians, with limited literature on potential quantitative objective measures.Aims: This study investigated whether an acoustic measure quantifying degree of lexical stress contrastiveness in three syllable words, produced in isolation and in a carrier sentence, differentiated individuals with AOS with/without aphasia (AOS), aphasia only (APH), and healthy controls (CTL).Methods & Procedures: Eight individuals with aphasia, nine with AOS plus aphasia and 8 age-matched control participants named pictures of strong-weak and weak-strong polysyllabic words in isolation and in a declarative carrier sentence. Pairwise Variability Indices (PVI) were used to measure the normalised relative vowel duration and peak intensity over the first two syllables of the polysyllabic words.Outcomes & Results: Individuals with aphasia performed similarly to control participants in all conditions. AOS participants demonstrated significantly lower PVI_vowel duration values for words with weak-strong stress produced in the sentence condition only, compared to controls and individuals with aphasia. This was primarily due to disproportionately long vowels in the word-initial weak syllable for AOS participants. There was no difference among groups on PVI_intensity.Conclusions: The finding of reduced lexical stress contrastiveness for weak-strong words in sentences for individuals with mild to moderate-severe AOS is consistent with the perceptual diagnostic feature of equal stress in AOS. Findings provide support for use of the objective PVI_vowel duration measure to help differentiate individuals with AOS (with/without aphasia), from those with aphasia only. Future research is warranted to explore the utility of this acoustic measure, and others, for reliable diagnosis of AOS.

AB - Background: Apraxia of Speech (AOS) is partly characterised by impaired production of prosody in words and sentences. Identification of dysprosody is based on perceptual judgements of clinicians, with limited literature on potential quantitative objective measures.Aims: This study investigated whether an acoustic measure quantifying degree of lexical stress contrastiveness in three syllable words, produced in isolation and in a carrier sentence, differentiated individuals with AOS with/without aphasia (AOS), aphasia only (APH), and healthy controls (CTL).Methods & Procedures: Eight individuals with aphasia, nine with AOS plus aphasia and 8 age-matched control participants named pictures of strong-weak and weak-strong polysyllabic words in isolation and in a declarative carrier sentence. Pairwise Variability Indices (PVI) were used to measure the normalised relative vowel duration and peak intensity over the first two syllables of the polysyllabic words.Outcomes & Results: Individuals with aphasia performed similarly to control participants in all conditions. AOS participants demonstrated significantly lower PVI_vowel duration values for words with weak-strong stress produced in the sentence condition only, compared to controls and individuals with aphasia. This was primarily due to disproportionately long vowels in the word-initial weak syllable for AOS participants. There was no difference among groups on PVI_intensity.Conclusions: The finding of reduced lexical stress contrastiveness for weak-strong words in sentences for individuals with mild to moderate-severe AOS is consistent with the perceptual diagnostic feature of equal stress in AOS. Findings provide support for use of the objective PVI_vowel duration measure to help differentiate individuals with AOS (with/without aphasia), from those with aphasia only. Future research is warranted to explore the utility of this acoustic measure, and others, for reliable diagnosis of AOS.

UR - http://www.scopus.com/inward/record.url?scp=84896544905&partnerID=8YFLogxK

U2 - 10.1080/02687038.2014.889275

DO - 10.1080/02687038.2014.889275

M3 - Article

VL - 28

SP - 554

EP - 575

JO - Aphasiology

T2 - Aphasiology

JF - Aphasiology

SN - 0268-7038

IS - 5

ER -