Biomedical subjects

G J Docherty

Publications and source records attributed to G J Docherty.

4 recordsLinked to original sources

PubMed2001

Prosodic variation across sampling tasks in normal and dysarthric speakers.

Speech assessments are commonly based on structured elicitation tasks. Despite the value of these tasks, the extent to which their results are a valid reflection of natural speech performance is being increasingly questioned. This is particularly warranted in the light of research findings indicating significant differences in normal speech behaviour across sampling tasks. There is, however, a paucity of research into how disordered speakers' performance varies across elicitation tasks. This study investigated ten prosodic parameters in structured and unstructured speech tasks (reading and conversation) in 12 dysarthric and 12 control subjects. The results suggest that the nature of sampling task affected dysarthric speakers differently to the control group. The implications of these findings for the assessment of disordered speakers are addressed.

Aged↗

PubMed1999

A study of the effectiveness of voice therapy in the treatment of 45 patients with nonorganic dysphonia.

Forty-five patients diagnosed as having nonorganic dysphonia were assigned in rotation to 1 of 3 groups. Patients in group 1 received no treatment and acted as a control group. Patients in groups 2 and 3 received a program of indirect therapy and direct with indirect therapy, respectively. A range of qualitative and quantitative measures were carried out on all patients before and after treatment to evaluate change in voice quality over time. Results revealed a significant difference between the 3 treatment groups in the amount of change for the voice severity, electrolaryngograph, and shimmer measurements and on ratings provided by a patient questionnaire (P<0.05). However, other measures failed to show significant differences between the 3 groups. Most of the patients (86%) in group 1 showed no significant change on any of the measures. Some patients in treatment group 2 (46%) showed significant change in voice quality. Fourteen out of 15 patients (93%) in treatment group showed significant changes in voice quality.

Adolescent↗

PubMed1998

The effectiveness of voice therapy for patients with non-organic dysphonia.

Forty-five patients diagnosed as having non-organic dysphonia were assigned in rotation to one of three groups. Patients in one group received no treatment and acted as a control group. Patients in the other two groups received a programme of either 'indirect' therapy or 'direct with indirect' therapy, respectively. A self-report questionnaire of vocal performance, observed ratings of voice quality, and computer-derived acoustic measurements (signal-to-noise ratio, pitch perturbation and amplitude perturbation) were carried out on all patients before and after treatment to evaluate the changes in voice quality over time. There was a significant difference between the three groups on the self-report questionnaire, voice quality ratings and pitch perturbation measurements (P = < 0.05). Thirteen out of 15 control patients showed no significant change on any of the measures. Seven patients who received indirect treatment showed significant improvement in voice quality following treatment. Fourteen out of 15 patients who received direct treatment showed significant improvement in voice quality.

Adult↗

PubMed1995

Phonetic variation in dysarthric speech as a function of sampling task.

Previous studies have demonstrated a number of ways in which normal speakers' phonetic performance varies across reading and spontaneous speech tasks. This study set out to investigate whether similar differences across speech sampling tasks were found in a mixed group of dysarthric subjects. A selection of segmental and prosodic parameters were investigated acoustically in the performance of five mild dysarthric speakers and five matched control subjects. The results demonstrated that breath-pause position, unstressed vowel duration and voice-onset time were subject to variation across sampling task in the speech produced by different types of dysarthric speaker. The results suggest that read material produced by dysarthric speakers may not be wholly representative of those speakers' spontaneous speech. Preliminary implications for clinical practice are discussed. The findings point to the need for further research to investigate the extent of such differences and their implications for dysarthria assessment, which up to the present has relied predominantly on read material.

Adult↗