Jacqueline S. Laures

Acoustic and intelligibility characteristics of sentence production in neurogenic speech disorders.

The purpose of this study was to examine the relationship between scaled speech intelligibility and selected acoustic variables in persons with dysarthria. Control speakers and speakers with amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD) produced sentences which were analyzed acoustically and perceptually. The acoustic variables included total utterance durations, segment durations, estimates of the acoustic vowel space, and slopes of formant transitions; the perceptual variables included scaled speech intelligibility and severity of speech involvement. Results indicated that the temporal variables typically differentiated the ALS group, but not the PD group, from the controls, and that vowel spaces were smaller for both neurogenic groups as compared to controls, but only significantly so for the ALS speakers. The relation of these acoustic measures to scaled speech intelligibility is shown to be complex, and the composite results are discussed in terms of sentence vs. single-word intelligibility estimates and their underlying acoustic bases.

Effect of speaking rate manipulations on acoustic and perceptual aspects of the dysarthria in amyotrophic lateral sclerosis

The current study explored the acoustic and perceptual effects of speaking rate adjustments in persons with amyotrophic lateral sclerosis (ALS) and in neurologically normal individuals. Sentence utterances were obtained from the participants at two self-selected speaking rates: habitual and fast. Total utterance durations, segment durations, and vowel formant frequencies comprised the acoustic measures, whereas magnitude estimates of speech intelligibility and severity of speech involvement were the perceptual measures. Results showed that participants in both the neurologically normal and ALS groups were able to increase their speaking rate when asked to do so, but that the participants with ALS were significantly slower than the neurologically normal participants at both rates. Both groups of participants also showed compression of the acoustic vowel space with increased speaking rate, with the vowel spaces of participants with ALS generally being more compressed than the vowel spaces of neurologically normal participants, at either rate. Most importantly, the perceptual measures failed to show any effect of the speaking rate adjustment on scaled intelligibility or severity, for either group. These findings are discussed relative to the general issue of slow habitual speaking rates among many speakers with dysarthria, and possible explanations for the slowness. The lack of an effect of increased rate on the perception of the speech deficit among speakers with ALS argues against the idea that the habitually slow rates are a form of compensation to reduce the complexity of speech production.

Perceptual effects of a flattened fundamental frequency at the sentence level under different listening conditions.

UNLABELLED The purpose of this series of experiments was to examine the effect of a flattened fundamental frequency (F0) contour on the intelligibility of sentence length material in different listening environments. Eight speakers of different genders and ages produced sentences from the Speech Perception in Noise Test (SPIN). Each utterance was subjected to a resynthesis technique that allowed flattening of the fundamental frequency while maintaining the timing and spectral characteristics of the utterances. To avoid learning effects two groups of listeners were chosen to complete word transcription and interval scaling tasks of the unmodified and flattened F0 utterances under different listening conditions (competing white noise or multi-speaker babble) to obtain measures of speech intelligibility. Results were that a flattened fundamental frequency contour negatively influences speech intelligibility regardless of the nature of the competing background noise. LEARNING OUTCOMES (1) To appreciate the role fundamental frequency variation plays in speech intelligibility. (2) To understand the importance of considering environmental noise in clinical speech intelligibility testing.

Arousal and auditory vigilance in individuals with aphasia during a linguistic and nonlinguistic task

Background: Attentional deficits have been observed in individuals with aphasia. Attention, specifically vigilance, is believed to be related to arousal. However, our understanding of arousal and its impact on vigilance performance in individuals with aphasia is very limited. Aims: The purpose of the current study was to investigate whether there is nonoptimal arousal in individuals with aphasia that would affect auditory processing of linguistic and nonlinguistic stimuli. Additionally, this study explored whether there was generalised, nonoptimal arousal and impaired vigilance or deficits specific to linguistic processing. Methods & Procedures: A total of 20 males (10 with left‐hemisphere stroke and aphasia and 10 nonbrain‐damaged controls) participated in this study. Physiologic arousal indexed by cardiovascular and neuroendocrine measures and vigilance performance was compared between the two groups during linguistic and nonlinguistic vigilance tasks. Outcomes & Results: Results indicated that arousal levels and vigilance performance differed between the two groups. However, within groups arousal and vigilance did not differ between the linguistic and nonlinguistic tasks. Conclusions: The present findings suggest that individuals with aphasia have decreased overall vigilance and nonoptimal arousal regardless of the linguistic or nonlinguistic nature of the stimuli.

Complementary and alternative medical approaches to treating adult neurogenic communication disorders: a review.

Purpose: This paper reviews studies investigating the effectiveness of treating adult neurogenic communication disorders with complementary and alternative medicines (CAM). CAM is gradually experiencing recognition as a viable treatment approach for a variety of disorders by practitioners and patients. Some patients are using CAM as an adjunct to traditional rehabilitation. Additionally, speech-language pathologists are increasingly using CAM in treating communication disorders. Method: This review provides a description of various CAM techniques including acupuncture, hypnosis, relaxation training, dreamwork, biofeedback and homeopathy/herbal medicine. Investigations exploring the effectiveness of each of these approaches as they have been applied to aphasia, motor speech disorders, and cognitive impairments are discussed. Results and Conclusions: Little scientific inquiry into the effectiveness of CAM in the treatment of aphasia, motor speech disorders, and cognitive impairments has occurred. Many of the reviewed studies demonstrate inconsistent results; use limited sample sizes; do not include quantitative measures of cognitive, linguistic or motor speech skills; and are poorly reported. This review suggests that further exploration of this area is required before any strong conclusions regarding effectiveness and efficacy of these techniques can be made.

Acoustic and intelligibility characteristics of sentence production in neurogenic speech disorders

The purpose of this study was to examine the relationship between scaled speech intelligibility and selected acoustic variables in persons with dysarthria. Control speakers and speakers with amyotrophic lateral sclerosis (ALS) and Parkinsons disease (PD) produced sentences which were analyzed acoustically and perceptually. The acoustic variables included total utterance durations, segment durations, estimates of the acoustic vowel space, and slopes of formant transitions; the perceptual variables included scaled speech intelligibility and severity of speech involvement. Results indicated that the temporal variables typically differentiated the ALS group, but not the PD group, from the controls, and that vowel spaces were smaller for both neurogenic groups as compared to controls, but only significantly so for the ALS speakers. The relation of these acoustic measures to scaled speech intelligibility is shown to be complex, and the composite results are discussed in terms of sentence vs. single-word intelligibility estimates and their underlying acoustic bases.

Comparison of speech intelligibility measures

The speech intelligibility of dysarthric speakers is perceptually measured by one of the following four techniques: direct magnitude estimation with a modulus, free modulus magnitude estimation, interval scaling, and transcription. Weismer and Laures (2002) suggest that magnitude estimates may provide a more complete representation of speech intelligibility than other methods of measurement because it may be more sensitive to non‐segmental aspects of speech, such as prosody. However, the empirical data supporting such a statement is quite limited. The purpose of the current study is to explore the relationship of the four different measurement techniques to determine if one approach may provide a more accurate determination of the speech intelligibility of dysarthric speakers. Twelve listeners measured the speech of six dysarthric speakers and two healthy control speakers using the four different measurement techniques. Each speaker produced three sentences twice. The sentences were presented via a loudsp...