Network fingerprint of stimulation-induced speech impairment in essential tremor

ObjectiveTo gain insights into structural networks associated with stimulation-induced dysarthria (SID) and to predict stimulation-induced worsening of intelligibility in essential tremor patients with bilateral thalamic deep brain stimulation (DBS).MethodsMonopolar reviews were conducted in 14 essential tremor patients. Testing included determination of SID thresholds, intelligibility ratings and a fast syllable repetition task. Volumes of tissue activated (VTAs) were calculated to identify discriminative fibers for stimulation-induced worsening of intelligibility in a structural connectome. The resulting fiber-based atlas structure was than validated in a leave-one-out design.ResultsFibers determined as discriminative for stimulation-induced worsening of intelligibility were mainly connected to the ipsilateral precentral gyrus as well as to both cerebellar hemispheres and the ipsilateral brainstem. In the thalamic area, they ran laterally to the thalamus and postero-medially to the subthalamic nucleus, in close proximity, mainly antero-laterally, to fibers beneficial for tremor control as published by Al-Fatly et al. (2019). The overlap of the respective clinical stimulation setting’s VTAs with these fibers explained 62.4% (p<0.001) of the variance of stimulation-induced change in intelligibility in a leave-one out analysis.InterpretationThis study demonstrates that SID in essential tremor patients is associated with both, motor cortex and cerebellar connectivity. Furthermore, the identified fiber-based atlas structure might contribute to future postoperative programming strategies to achieve optimal tremor control without speech impairment in ET patients with thalamic DBS.

Effects of Rate Manipulation on Intelligibility in Children With Cerebral Palsy

Purpose We evaluated the effects of a speech supplementation strategy to reduce rate and improve intelligibility in children with cerebral palsy. Method Twenty-five children with cerebral palsy ( M age = 12.08 years) completed a structured speaking task in 2 speech conditions: habitual speech and slow speech. Fifteen children had mild intelligibility deficits; 10 had moderate–severe intelligibility deficits. In each condition, children repeated utterances of 2–7 words in length. In the habitual speech condition, children used their natural and unaltered speaking rate. In the slow speech condition, children were cued to insert pauses between words. Intelligibility ratings were obtained from orthographic transcriptions by unfamiliar adult listeners ( n = 100). Speech rate, in words per minute, was measured for each utterance. Results All children, regardless of severity group, were able to reduce their rate of speech when implementing the slow speech strategy. Only children in the moderate–severe group showed an improvement in intelligibility when implementing the slow speech strategy. Although there was considerable individual variability, there was a greater improvement in intelligibility for longer utterances compared to shorter ones. Conclusion A slow speech strategy may be beneficial for children with moderate–severe intelligibility deficits who speak in longer utterances. Future studies should seek to further examine the clinical feasibility of slow speech for children with reduced intelligibility.

Effect of the Visual Presentation of a Craniofacial Syndrome on Speech Intelligibility in Noise

Objective: Research has argued that a speaker’s facial appearance can result in an “intelligibility cost” for the listener. The study investigated whether such an intelligibility cost exists for a visible repaired cleft lip and nasal asymmetry. Setting: University department. Participants: Eight typical speakers provided speech samples. Twenty-eight naive listeners participated in a speech in noise experiment. Interventions: Listeners transcribed sentences in noise that were paired with faces of individuals with repaired cleft lip and nasal asymmetry or typical faces. They also rated speaker intelligibility and answered a questionnaire about their previous knowledge about cleft lip and palate. Main Outcome Measures: Percentage of words transcribed correctly and intelligibility ratings, compared by experimental condition (photo of typical face or face with repaired cleft lip and nasal asymmetry) and speaker gender. Results: There were no statistically significant differences between speech stimuli that were presented with faces with repaired cleft lip and nasal asymmetry or typical faces. The percentage of words transcribed correctly by the listeners was lower for female speakers ( F = 12.7, df = 1; P < .01). Speech intelligibility of female speakers was rated more poorly ( F = 10.5, df = 1; P < .01). Conclusions: Presence of a repaired cleft lip and nasal asymmetry did not result in an intelligibility cost for naive listeners. Future research should investigate possible effects of facial motion or previous knowledge.

The Effects of Intensive Speech Treatment on Conversational Intelligibility in Spanish Speakers With Parkinson's Disease

Purpose The purpose of this study was to examine the effects of intensive speech treatment on the conversational intelligibility of Castilian Spanish speakers with Parkinson's disease (PD), as well as on the speakers' self-perceptions of disability. Method Fifteen speakers with a medical diagnosis of PD participated in this study. Speech recordings were completed twice before treatment, immediately posttreatment, and at a 1-month follow-up session. Conversational intelligibility was assessed in 2 ways—transcription accuracy scores and intelligibility ratings on a 9-point Likert scale. The Voice Handicap Index (Núñez-Batalla et al., 2007) was administered as a measure of self-perceived disability. Results Group data revealed that transcription accuracy and median ease-of-understanding ratings increased significantly immediately posttreatment, with gains maintained at the 1-month follow-up. The functional subscale of the Voice Handicap Index decreased significantly posttreatment, suggesting a decrease in perceived communication disability after speech treatment. Conclusion These findings support the implementation of intensive voice treatment to improve conversational intelligibility in Spanish speakers with PD with dysarthria as well as to improve the speakers' perception of their daily communicative capabilities. Clinical and theoretical considerations are discussed.

Receptive Vocabulary, Cognitive Flexibility, and Inhibitory Control Differentially Predict Older and Younger Adults' Success Perceiving Speech by Talkers With Dysarthria

Purpose Previous research has demonstrated equivocal findings related to the effect of listener age on intelligibility ratings of dysarthric speech. The aim of the present study was to investigate the mechanisms that support younger and older adults' perception of speech by talkers with dysarthria. Method Younger and older adults identified words in phrases produced by talkers with dysarthria. Listeners also completed assessments on peripheral hearing, receptive vocabulary, and executive control functions. Results Older and younger adults did not differ in their ability to perceive speech by talkers with dysarthria. Younger adults' success in identifying words produced by talkers with dysarthria was associated only with their hearing acuity. In contrast, older adults showed effects of working memory and cognitive flexibility and interactions between hearing acuity and receptive vocabulary and between hearing acuity and inhibitory control. Conclusions Although older and younger adults had equivalent performance identifying words produced by talkers with dysarthria, older adults appear to utilize more cognitive support to identify those words.

Acoustic and Perceptual Consequences of Speech Cues for Children With Dysarthria

Purpose Reductions in articulatory working space and vocal intensity have been linked to intelligibility deficits in children with dysarthria due to cerebral palsy. However, few studies have examined the outcomes of behavioral treatments aimed at these underlying impairments or investigated which treatment cues might best facilitate improved intelligibility. This study assessed the effects of cues targeting clear speech (i.e., “Speak with your big mouth”) and greater vocal intensity (i.e., “Speak with your strong voice”) on acoustic measures of speech production and intelligibility. Method Eight children with spastic dysarthria due to cerebral palsy repeated sentence- and word-level stimuli across habitual, big mouth, and strong voice conditions. Acoustic analyses were conducted, and 48 listeners completed orthographic transcription and scaled intelligibility ratings. Results Both cues resulted in significant changes to vocal intensity and speech rate although the degree of change varied by condition. In a similar manner, perceptual analysis revealed significant improvements to intelligibility with both cues; however, at the single-word level, big mouth outperformed strong voice. Conclusion Children with dysarthria are capable of changing their speech styles differentially in response to cueing. Both the big mouth and strong voice cues hold promise as intervention strategies to improve intelligibility in this population. Supplemental Material https://doi.org/10.23641/asha.5116843

Accent evaluation from extemporaneous child speech

A key issue in judging foreign accent is to isolate the phonetic component from potentially confounding higher-level factors such as grammatical or prosodic errors which arise when using natural sentence-length speech material. The current study evaluated accent and intelligibility ratings of children’s speech for isolated words spliced out of extemporaneous material elicited via a picture description task. Experiment 1 demonstrated that word scores and accent ratings provided by native judges pattern as in earlier studies, validating the use of word-based material derived from natural speech. In a second experiment, listeners rated the degree of foreign accent and comprehensibility for unrelated sequences of 1 to 8 words from the same talker. Degree of foreign accent was judged to increase with sequence length, asymptoting by 2 word sequences, although listeners did not rate the sequence based on the most-accented word it contains. Comprehensibility was judged to be lower as sequence length increased, asymptoting at 4 words. These findings suggest that short sequences of randomly-permuted words extracted from extemporaneous speech can be used for robust accent and comprehensibility judgements whose focus is on the phonetic basis for deviations from the native norm.

Perception of Speech Produced by Native and Nonnative Talkers by Listeners with Normal Hearing and Listeners with Cochlear Implants

Purpose The aim of this study was to evaluate the understanding of English sentences produced by native (English) and nonnative (Spanish) talkers by listeners with normal hearing (NH) and listeners with cochlear implants (CIs). Method Sentence recognition in noise was measured in adult subjects with CIs and subjects with NH, all of whom were native talkers of American English. Test sentences were from the Hearing in Noise Test (HINT) database and were produced in English by four native and eight nonnative talkers. Subjects also rated the intelligibility and accent for each talker. Results The speech recognition thresholds in noise of subjects with CIs and subjects with NH were 4.23 dB and 1.32 dB poorer with nonnative talkers than with native talkers, respectively. Performance was significantly correlated with talker intelligibility and accent ratings for subjects with CIs but only correlated with talker intelligibility ratings for subjects with NH. For all subjects, performance with individual nonnative talkers was significantly correlated with talkers' number of years of residence in the United States. Conclusion CI users exhibited a larger deficit in speech understanding with nonnative talkers than did subjects with NH, relative to native talkers. Nonnative talkers' experience with native culture contributed strongly to speech understanding in noise, intelligibility ratings, and accent ratings of both listeners with NH and listeners with CIs.