A pilot study shows the positive effects of continuous airway pressure for treating hypernasal speech in children with infantile-onset Pompe disease

Children with infantile-onset Pompe disease (IOPD) demonstrate hypernasality. This study aimed to evaluate whether continuous positive airway pressure (CPAP) training may reduce hypernasality in children with IOPD. Five children with IOPD were enrolled in a single-subject experimental design of type A-B-A′. The intervention comprised an 8-week, 6-day-per-week regimen of CPAP training at home. Participants continued traditional speech therapy once per week throughout the 24-week study duration. The outcome measurements included the degree of hypernasality (DH), the percentage of consonants correct (PCC), and the speech intelligibility score (SIS). C-statistic analysis with an α of 0.05 was used along with visual analysis to assess speech changes. Three patients completed the study. During the CPAP training phase, the DH, PCC, and SIS were significantly improved compared with the baseline (p < 0.05). At the follow-up phase, both DH and SIS were improved compared with the baseline (p < 0.05), but the PCC had returned to the baseline level. CPAP training demonstrated effectiveness in reducing nasal sounds in IOPD patients. Further studies training younger children with normal hearing may help elucidate the persistence of the effects in children with IOPD.

Treating Hypernasal Speech in Children with Infantile-Onset Pompe Disease: Effectiveness of Continuous Positive Airway Pressure

Children with infantile-onset Pompe disease (IOPD) demonstrate hypernasality. This study aimed to evaluate whether continuous positive airway pressure (CPAP) training, effective in reducing hypernasality in subjects with velopharyngeal insufficiency, may reduce hypernasality in children with IOPD. Five children with IOPD were enrolled to partake in an 8-week, 6-day-per-week regimen of CPAP training at home, involving 8 week baseline, 8 week CPAP training, and 8 week follow-up outcome assessment combined with regular speech therapy once per week. The outcomes included the degree of hypernasality (DH), the percentage of consonants correct (PCC), and the speech intelligibility score (SIS). C-statistic analysis with an α of .05 (z ≥ 1.645) and visual analysis were used to assess speech changes. Three patients completed the study. During the CPAP training phase, the DH, PCC, and SIS were significantly improved compared with the baseline (p ≤ .05). At the follow-up phase, both DH and SIS were improved compared with the baseline (p ≤ .05), but the PCC had returned to the baseline level (p ≥ .05). CPAP training demonstrated effectiveness in reducing nasal sounds in IOPD patients. Further studies involving training younger children with normal hearing may help elucidate the persistence of the effects in children with IOPD.

Generalized Learning of Dysarthric Speech Between Male and Female Talkers

Purpose Perceptual training is a listener-targeted means for improving intelligibility of dysarthric speech. Recent work has shown that training with one talker generalizes to a novel talker of the same sex and that the magnitude of benefit is maximized when the talkers are perceptually similar. The current study expands previous findings by investigating whether perceptual training effects generalize between talkers of different sex. Method Forty new listeners were recruited for this study and completed a pretest, familiarization, and posttest perceptual training paradigm. Historical data collected using the same three-phase protocol were included in the data analysis. All listeners were exposed to the same talker with dysarthria during the pretest and posttest phases. For the familiarization phase, listeners were exposed to one of four talkers with dysarthria, differing in sex and level of perceptual similarity to the test talker or a control talker. During the testing phases, listener transcribed phrases produced by the test talker with dysarthria. Listener transcriptions were then used to calculate a percent words correct intelligibility score. Results Multiple linear regression analysis revealed that intelligibility at posttest was not predicted by sex of the training talker. Consistent with earlier work, the magnitude of intelligibility gain was greater when the familiarization and test talkers were perceptually similar. Additional analyses revealed greater between-listeners variability in the dissimilar conditions as compared to the similar conditions. Conclusions Learning as a result of perceptual training with one talker with dysarthria generalized to another talker regardless of sex. In addition, listeners trained with perceptually similar talkers had greater and more consistent intelligibility improvement. Together, these results add to previous evidence demonstrating that learning generalizes to novel talkers with dysarthria and that perceptual training is suitable for many listeners.

Listening Effort Is Not the Same as Speech Intelligibility Score

Listening effort is a valuable and important notion to measure because it is among the primary complaints of people with hearing loss. It is tempting and intuitive to accept speech intelligibility scores as a proxy for listening effort, but this link is likely oversimplified and lacks actionable explanatory power. This study was conducted to explain the mechanisms of listening effort that are not captured by intelligibility scores, using sentence-repetition tasks where specific kinds of mistakes were prospectively planned or analyzed retrospectively. Effort measured as changes in pupil size among 20 listeners with normal hearing and 19 listeners with cochlear implants. Experiment 1 demonstrates that mental correction of misperceived words increases effort even when responses are correct. Experiment 2 shows that for incorrect responses, listening effort is not a function of the proportion of words correct but is rather driven by the types of errors, position of errors within a sentence, and the need to resolve ambiguity, reflecting how easily the listener can make sense of a perception. A simple taxonomy of error types is provided that is both intuitive and consistent with data from these two experiments. The diversity of errors in these experiments implies that speech perception tasks can be designed prospectively to elicit the mistakes that are more closely linked with effort. Although mental corrective action and number of mistakes can scale together in many experiments, it is possible to dissociate them to advance toward a more explanatory (rather than correlational) account of listening effort.

Design and Development of a Speech Intelligibility Test Based on Pseudowords in French: Why and How?

Purpose The current intelligibility tests performed on speakers with atypical speech production are limited by the ability of listeners to restore distorted sequences. This results in a measure that is overvalued when compared with the real articulatory performance. In this article, we present a new intelligibility test in order to neutralize the commonly encountered bias in traditional perception-based assessments. We present the construction of the acoustic–phonetic decoding task and its first test during a perceptual judgment test of intelligibility and during a result comparison with a global perceptual evaluation. Method We developed a very large pseudoword directory including about 90,000 forms that respect French phonotactic constraints. From this directory, we have created lists of pseudowords intended to be recorded for the constitution of the corpus. These lists are established due to an algorithm integrating predefined linguistic constraints and produced by 47 speakers (nine healthy and 38 patients). We then performed a perceptual judgment of intelligibility test with 20 listeners who transcribed these productions. Results At the end of the data processing stage, we obtained a Perceived Phonological Deviation (PPD) score for each speaker that reflects the average number of features altered per phoneme. We then compared the PPD score with a global intelligibility score derived from a global perceptual assessment of intelligibility and of the alteration severity. Conclusions The current findings confirm that a speech intelligibility test based on pseudowords in French achieves fine-grained PPD scores, which enables discrimination between patients and healthy speakers. Moreover, the PPD score is related to the global intelligibility score, especially in severity. Further studies are needed to better understand the discrimination power of this intelligibility test based on an acoustic–phonetic decoding task.

Efficient Adaptive Speech Reception Threshold Measurements Using Stochastic Approximation Algorithms

This study examines whether speech-in-noise tests that use adaptive procedures to assess a speech reception threshold in noise ( SRT50n) can be optimized using stochastic approximation (SA) methods, especially in cochlear-implant (CI) users. A simulation model was developed that simulates intelligibility scores for words from sentences in noise for both CI users and normal-hearing (NH) listeners. The model was used in Monte Carlo simulations. Four different SA algorithms were optimized for use in both groups and compared with clinically used adaptive procedures. The simulation model proved to be valid, as its results agreed very well with existing experimental data. The four optimized SA algorithms all provided an efficient estimation of the SRT50n. They were equally accurate and produced smaller standard deviations (SDs) than the clinical procedures. In CI users, SRT50n estimates had a small bias and larger SDs than in NH listeners. At least 20 sentences per condition and an initial signal-to-noise ratio below the real SRT50n were required to ensure sufficient reliability. In CI users, bias and SD became unacceptably large for a maximum speech intelligibility score in quiet below 70%. In conclusion, SA algorithms with word scoring in adaptive speech-in-noise tests are applicable to various listeners, from CI users to NH listeners. In CI users, they lead to efficient estimation of the SRT50n as long as speech intelligibility in quiet is greater than 70%. SA procedures can be considered as a valid, more efficient, and alternative to clinical adaptive procedures currently used in CI users.

Effects of classroom acoustics on speech intelligibility and response time: A comparison between native and non-native listeners

This study evaluates the speech reception performance of native (L1) and non-native (L2) normal-hearing young adults in acoustical conditions containing varying amounts of reverberation and background noise. Two metrics were used and compared: the intelligibility score and the response time, taken as a behavioral measure of listening effort. Listening tests were conducted in auralized acoustical environments with L1 and L2 English-speaking university students. It was found that even though the two groups achieved the same, close to the maximum accuracy, L2 participants manifested longer response times in every acoustical condition, suggesting an increased involvement of cognitive resources in the speech reception process.

Chinese speech intelligibility of children in noisy and reverberant environments

Reverberation time and signal-to-noise ratio in classrooms are critical factors to speech intelligibility. In this study, the combined effect of reverberation time and signal-to-noise ratio on Chinese speech intelligibility of children was investigated in 28 elementary school classrooms in China. The results show that Chinese speech intelligibility scores increase with an increase of signal-to-noise ratio and the age of children, and decrease with an increase of reverberation time in classrooms. Younger children require higher signal-to-noise ratio and shorter reverberation time than older children to understand the speech. The A-weighted signal-to-noise ratio combined with a wide range of reverberation time can be used to predict speech intelligibility score and serve as a criterion for classroom design for elementary schools.

The Effect of Background Noise on Intelligibility of Dysphonic Speech

Purpose The aim of this study is to determine the effect of background noise on the intelligibility of dysphonic speech and to examine the relationship between intelligibility in noise and an acoustic measure of dysphonia: cepstral peak prominence (CPP). Method A study of speech perception was conducted using speech samples from 6 adult speakers with typical voice and 6 adult speakers with dysphonia. Speech samples were presented to 30 listeners with typical hearing in 3 noise conditions: quiet, signal-to-noise ratio (SNR)+5, and SNR+0. Intelligibility scores were obtained via orthographic transcription as the percentage of correctly identified words. Speech samples were acoustically analyzed using CPP, and the correlation between the CPP measurements and intelligibility scores was examined. Results The intelligibility of both typical and dysphonic speech was reduced as the level of background noise increased. The reduction was significantly greater in dysphonic speech. A strong correlation was noted between CPP and intelligibility score at SNR+0. Conclusions Dysphonic speech is relatively harder to understand in the presence of background noise as compared with typical speech. CPP may be a useful predictor of this intelligibility deficit. Future work is needed to confirm these findings with a larger number of speakers and speech materials with known predictability.