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J H Ryalls

Publications and source records attributed to J H Ryalls.

7 recordsLinked to original sources
PubMed1987

On the nature of the foreign accent syndrome: a case study.

A detailed acoustic analysis was conducted of the speech production of a single patient presenting with the foreign accent syndrome subsequent to a left-hemisphere stroke in the subcortical white matter of the pre-rolandic and post-rolandic gyri at the level of the body of the lateral ventricle. It was the object of this research to determine those changes which contribute to the perception of a "foreign accent." A number of acoustic parameters were investigated, including features of consonant production relating to voice, place, and manner of articulation, vowel production relating to vowel quality and duration, and speech melody relating to fundamental frequency. The results indicated that many attributes which might have contributed to the foreign quality of the patient's speech were similar to those of normal English speakers. However, a number of critical elements involving consonant and vowel production and intonation were impaired. It was hypothesized that the acoustically anomalous features are linked to a common underlying deficit relating to speech prosody. It is suggested that the normal listener categorizes this speech pattern as a foreign accent because the anomalous speech characteristics, while not a part of the English phonetic inventory, reflect stereotypical features which are a part of the universal phonetic properties found in natural language.

Cerebrovascular Disorders↗
PubMed1986

An acoustic study of vowel production in aphasia.

A group of five anterior and seven posterior aphasic patients were recorded for their vowel productions of the nine nondipthong vowels of American English and compared to a group of seven normal speakers. All phonemic substitutions were eliminated from the data base. A Linear Predictive Coding (LPC) computer program was used to extract the first and the second formant frequencies at the midpoint of the vowel for each of the remaining repetitions of the nine vowels. The vowel duration and the fundamental frequency of phonation were also measured. Although there were no significant differences in the formant frequency means across groups, there were significantly larger standard deviations for the aphasic groups compared to normals. Anterior aphasics were not significantly different from posterior aphasics with respect to this greater formant variability. There was a main effect for vowel duration means, but no individual group was significantly different from the other. Standard deviations of duration were significantly greater for the anterior aphasics compared to normal speakers, but not significantly different from posterior aphasics. Posterior aphasics did not have significantly greater standard deviations of duration than did normal subjects. Greater acoustic variability was considered to evidence a phonetic production deficit on the part of both groups of aphasic speakers, in the context of fairly well-preserved phonemic organization for vowels.

Adult↗
PubMed1984

Some acoustic aspects of fundamental frequency of CVC utterances in aphasia.

A set of 9 CVC utterances were elicited five times each from a group of 5 anterior and 7 posterior aphasics. These spoken tokens were acoustically analyzed for the fundamental frequency of phonation and compared to tokens for a group of 7 normal control speakers. Statistical analyses revealed that anterior aphasics produced significantly higher average fundamental frequencies than did normal speakers, and that both groups of aphasics had significantly greater variability (both inter- and intraspeaker) in their fundamental frequency values than did normal speakers. A subset of these data was also analyzed for the period-to-period variation or 'jitter' of the acoustic waveform. Each group was significantly different from each other: posterior aphasics demonstrated the greatest period-to-period variation followed by anterior aphasics and then normal subjects. Some implications of this research are discussed.

Aphasia↗
PubMed1982

Intonation in Broca's aphasia.

The intonation contours of the sentence "Construisons notre maison" produced by a group of Broca's aphasic patients were compared to those of this same sentence produced by a group of normal speakers. It was found that the Broca's aphasic patients demonstrated significantly restricted ranges of intonation when compared to the productions of the normal subjects. Different possible underlying mechanisms for this intonation compression are then discussed.

Adult↗
PubMedDate not supplied

Voice onset time in Spanish-English bilinguals: early versus late learners of English.

Thirty-two Hispanic speakers of English were evenly divided into two groups based on whether or not their initial learning of English began prior to, or after the age of 12 years. Each group had an even number of males (16) and females (16). The subjects were recorded producing a protocol of 18 basic speech syllables. The first three repetitions (54 tokens) were chosen for analysis. The 1728 tokens were digitized and measured for voice onset time (VOT). Findings support the hypothesis that the VOT values of Hispanics speaking English differ according to whether initial learning of English began prior to or after the age of 12 years. An analysis of variance (ANOVA) found significant main effects of group, place, voice, and gender. Significant interactions were group by voice, and voice by gender.

Adolescent↗