The effect of multitalker background noise on speech intelligibility in Parkinson\u27s disease and controls

This study investigated the effect of multi-talker background noise on speech intelligibility in participants with hypophonia due to Parkinson’s disease (PD). Ten individuals with PD and 10 geriatric controls were tested on four speech intelligibility tasks at the single word, sentence, and conversation level in various conditions of background noise. Listeners assessed speech intelligibility using word identification or orthographic transcription procedures. Results revealed non-significant differences between groups when intelligibility was assessed in no background noise. PD speech intelligibility decreased significantly relative to controls in the presence of background noise. A phonetic error analysis revealed a distinct error profile for PD speech in background noise. The four most frequent phonetic errors were glottal-null, consonant-null in final position, stop place of articulation, and initial position cluster-singleton. The results demonstrate that individuals with PD have significant and distinctive deficits in speech intelligibility and phonetic errors in the presence of background noise

Individual Differences in the Perceptual Learning of Degraded Speech: Implications for Cochlear Implant Aural Rehabilitation

abstract: In the noise and commotion of daily life, people achieve effective communication partly because spoken messages are replete with redundant information. Listeners exploit available contextual, linguistic, phonemic, and prosodic cues to decipher degraded speech. When other cues are absent or ambiguous, phonemic and prosodic cues are particularly important because they help identify word boundaries, a process known as lexical segmentation. Individuals vary in the degree to which they rely on phonemic or prosodic cues for lexical segmentation in degraded conditions. Deafened individuals who use a cochlear implant have diminished access to fine frequency information in the speech signal, and show resulting difficulty perceiving phonemic and prosodic cues. Auditory training on phonemic elements improves word recognition for some listeners. Little is known, however, about the potential benefits of prosodic training, or the degree to which individual differences in cue use affect outcomes. The present study used simulated cochlear implant stimulation to examine the effects of phonemic and prosodic training on lexical segmentation. Participants completed targeted training with either phonemic or prosodic cues, and received passive exposure to the non-targeted cue. Results show that acuity to the targeted cue improved after training. In addition, both targeted attention and passive exposure to prosodic features led to increased use of these cues for lexical segmentation. Individual differences in degree and source of benefit point to the importance of personalizing clinical intervention to increase flexible use of a range of perceptual strategies for understanding speech.Dissertation/ThesisDoctoral Dissertation Speech and Hearing Science 201

Factors influencing the efficacy of delayed auditory feedback in treating dysarthria associated with Parkinson\u27s disease

Parkinson\u27s disease patients exhibit a high prevalence of speech deficits including excessive speech rate, reduced intelligibility, and disfluencies. The present study examined the effects of delayed auditory feedback (DAF) as a rate control intervention for dysarthric speakers with Parkinson\u27s disease. Adverse reactions to relatively long delay intervals are commonly observed during clinical use of DAF, and seem to result from improper matching of the delayed signal. To facilitate optimal use of DAF, therefore, clinicians must provide instruction, modeling, and feedback. Clinician instruction is frequently used in speech-language therapy, but has not been evaluated during use of DAF-based interventions. Therefore, the primary purpose of the present study was to evaluate the impact of clinician instruction on the effectiveness of DAF in treating speech deficits. A related purpose was to compare the effects of different delay intervals on speech behaviors. An A-B-A-B single-subject design was utilized. The A phases consisted of a sentence reading task using DAF, while the B phases incorporated clinician instruction into the DAF protocol. During each of the 16 experimental sessions, speakers read with four different delay intervals (0 ms, 50 ms, 100 ms, and 150 ms). During the B phases, the experimenter provided verbal feedback and modeling pertaining to how precisely the speaker matched the delayed signal. Dependent variables measured were speech rate, percent intelligible syllables, and percent disfluencies. Three males with Parkinson\u27s disease and an associated dysarthria participated in the study. Results revealed that for all three speakers, DAF significantly reduced reading rate and produced significant improvements in either intelligibility (for Speaker 3) or fluency (for Speakers 1 and 2). A delay interval of 150 ms produced the greatest reductions in reading rates for all three speakers, although any of the DAF settings used was sufficient to produce significant improvements in either intelligibility or fluency. In addition, supplementing the DAF intervention with clinician instruction resulted in significantly greater gains achieved with DAF. These findings confirmed the effectiveness of various intervals of DAF in improving speech deficits in Parkinson\u27s disease speakers, particular when patients are provided with instruction and modeling from the clinician

The Effect of Botulinum Toxin Type A on Speech Intelligibility in Oromandibular Dystonia

Speech intelligibility of 10 individuals with OMD was measured before and after receiving BoNT-A injections. Intelligibility was assessed using the PIT (single-word intelligibility), SIT (sentence intelligibility), and a conversational speech task. Five listeners rated the speech intelligibility of these three intelligibility tasks via orthographic transcription and visual analogue scaling (VAS) techniques. BoNT-A was not associated with significant differences in speech intelligibility. Further analysis revealed a significant difference on the PIT VAS intelligibility ratings based on order of presentation, suggesting that listeners rated the first half of words on the PIT (words 1-29) as more intelligible than the second half of words (words 30-57). There was also a significant difference in SIT transcription intelligibility scores based on sentence length, suggesting that listeners rated shorter sentences with higher intelligibility than longer sentences. This research will contribute to a small body of literature on speech intelligibility in OMD

Towards a clinical assessment of acquired speech dyspraxia.

No standardised assessment exists for the recognition and quantification of acquired speech dyspraxia (also called apraxia of speech, AS). This thesis aims to work towards development of such an assessment based on perceptual features. Review of previous features claimed to characterise AS and differentiate it from other acquired pronunciation problems (dysarthrias; phonemic paraphasia - PP) has proved negative. Reasons for this have been explored. A reconceptualisation of AS is attempted based on physical studies of AS, PP and the dysarthrias; their position and relationship within coalitional models of speech production; by comparison with normal action control and other dyspraxias. Contrary to the view of many it is concluded that AS and PP are dyspraxias (albeit different types). However, due to the interactive nature of speech-language production and behaviour of the vocal tract as a functional whole AS is unlikely to be distinguishable in an absolute fashion based on single speech characteristics. Rather it is predicted that pronunciation disordered groups will differ relatively on total error profiles and susceptibility to associated effects (variability; propositionality; struggle; length-complexity; latency-utterance times). Using a prototype battery and refined error transcription and analysis procedures a series of studies test predictions on three groups: spastic dysarthrics (n = 6) AS and PP without (n = 12) and with (n = 12) dysphasia. The main conclusions do not support the error profile hypotheses in any straightforward manner. Length-complexity effects and latency-utterance times fail to consistently separate groups. Variability, propositionality and struggle proved the most reliable indicators. Error profiles remain the closest indicators of speakers' intelligibility and therapeutic goals. The thesis argues for a single case approach to differential diagnosis and alternative statistical analyses to capture individual and group differences. Suggestions for changes to the prototype clinical battery and data management to effect optimal speaker differentiation conclude the work

Spectral analysis of stop consonants in individuals with dysarthria secondary to stroke

Dysarthria refers to a group of neurogenic speech disorders which result in abnormal strength, speed, range, steadiness, tone, or accuracy of movements required for speech production. Although speech deficits of dysarthria are heterogeneous according to lesion sites and/or etiologies such as stroke, traumatic brain injury, cerebral palsy, Parkinson’s disease (PD), “imprecise consonants” has been known as one of the most prominent and frequently occurring features of dysarthria, which subsequently contributes to decreased speech intelligibility. The present study points out the paucity of acoustic data on consonants produced by speakers with dysarthria, especially by spectral analysis, and reports four spectral moment analysis results on word initial stop consonants in six individuals with dysarthria and six age and gender matched healthy individuals. Each participant was asked to say a series of single words with a carrier phrase and a set of sentences. The initial 40ms of each single word was analyzed using TF32 to find the spectral moment values. Results suggest that the first spectral moment (M1) was the most useful in differentiating between the genders, healthy vs. dysarthria, and place of articulation, which is consistent with previous studies. This moment revealed that individuals with dysarthria have higher values compared to healthy individuals, which indicates that this speaker group tends to have a more anterior constriction for stop production. Along with this fronting pattern, the M1 ratios between adjacent stops were reduced for the speakers with dysarthria, which indicates reduced acoustic contrast for stop production. However, no correlation was found between the perceptual speech intelligibility estimates and the spectral characteristics

Acoustic and perceptual assessment of stop consonants produced by normal and dysarthric speakers

Thesis (Ph.D.)--Harvard--Massachusetts Institute of Technology Division of Health Sciences and Technology, 2000.Includes bibliographical references (p. 286-290).by Kelly Lynn Poort.Ph.D

Case study of improving the speech intelligibility of children with Down syndrome using pacing boards

textThe present study was designed to answer the following questions: (a) Can a child with Down syndrome (DS) increase speech intelligibility using a pacing board through a modified Core Vocabulary Approach (CVA)? (b) What are the effects of the pacing board as an intervention tool on the speech skills of children with DS? (c) What is a valid measurement of improved speech intelligibility? In this case study, the pacing board was used as an intervention tool in conjunction with a modified CVA with one child with DS to examine whether a child with limited speech skills could increase her speech intelligibility to enhance communicative competence. Data was collected on the child’s speech production output patterns in order to provide information on the pacing board’s efficacy. Results indicated that the pacing board was an effective intervention tool for this child. Increases on various speech intelligibility metrics were evident. The child's improvements on indices examined in this study were slow but significant, relative to her previous speech and language status.Communication Sciences and Disorder