H. Timothy Bunnell

On enhancement of spectral contrast in speech for hearing‐impaired listeners

A digital processing method is described for altering spectral contrast (the difference in amplitude between spectral peaks and valleys) in natural utterances. Speech processed with programs implementing the contrast alteration procedure was presented to listeners with moderate to severe sensorineural hearing loss. The task was a three alternative (/b/,/d/, or /g/) stop consonant identification task for consonants at a fixed location in short nonsense utterances. Overall, tokens with enhanced contrast showed moderate gains in percentage correct stop consonant identification when compared to unaltered tokens. Conversely, reducing spectral contrast generally reduced percent correct stop consonant identification. Contrast alteration effects were inconsistent for utterances containing /d/. The observed contrast effects also interacted with token intelligibility.

VocaliD: personalizing text-to-speech synthesis for individuals with severe speech impairment

Speech synthesis options on assistive communication devices are very limited and do not reflect the users vocal quality or personality. Previous work suggests that speakers with severe speech impairment can control prosodic aspects of their voice, and often retain the ability to produce sustained vowel-like utterances. This project leverages these residual phonatory abilities in order to build an adaptive text-to-speech synthesizer that is intelligible, yet conveys the users vocal identity. Our VocaliD system combines the source characteristics of the disordered speaker with the filter characteristics of an age-matched healthy speaker using voice transformation techniques, in order to produce a personalized voice. Usability testing indicated that listeners were 94% accurate in transcribing morphed samples and 79.5% accurate in matching morphed samples from the same speaker.

Academic and Clinical Training in Cleft Palate for Speech-Language Pathologists

Objective: The purpose of this study was to obtain information about academic and clinical training of speech-language pathology students in cleft palate (CP). Methods: Representatives of 232 accredited graduate programs in speech-language pathology were invited via e-mail to complete a web-based 32-item questionnaire. Questions focused on the type and nature of courses offered related to CP, availability of clinical practica, and number of hours of clinical experience by students. An item-by-item analysis was conducted and descriptive statistics obtained. Results: A total of 127 (54.7%) of the programs responded. Sixty-seven percent offered coursework exclusively devoted to CP, and for 53% of these it was a required course. For the programs that did not offer an exclusive course on CP, 35% indicated that CP was covered in other courses such as articulation, voice, or anatomy and physiology. Fifty-four percent of the programs offered clinical practica in CP. For these, a median of five students of a median graduate speech-language pathology class of 43 were enrolled in practica involving CP (range  =  0–21), and students spent a median of 2 hours in practica involving CP (range  =  0–100). Conclusions: Cleft palate is a complex disorder to which many students have limited exposure and for which more graduate training is unlikely since the 1993 American Speech-Language-Hearing Association (ASHA) certification changes. As a result, there is a need to look towards alternative methods to enhance the educational and clinical experiences of students and practitioners in cleft palate.

Use of mobile devices and the internet for multimedia informed consent delivery and data entry in a pediatric asthma trial: Study design and rationale☆

INTRODUCTION Phase III/IV clinical trials are expensive and time consuming and often suffer from poor enrollment and retention rates. Pediatric trials are particularly difficult because scheduling around the parent, participant and potentially other sibling schedules can be burdensome. We are evaluating using the internet and mobile devices to conduct the consent process and study visits in a streamlined pediatric asthma trial. Our hypothesis is that these study processes will be non-inferior and will be less expensive compared to a traditional pediatric asthma trial. MATERIALS/METHODS Parents and participants, aged 12 through 17 years, complete the informed consent process by viewing a multi-media website containing a consent video and study material in the streamlined trial. Participants are provided an iPad with WiFi and EasyOne spirometer for use during FaceTime visits and online twice daily symptom reporting during an 8-week run-in followed by a 12-week study period. Outcomes are compared with participants completing a similarly designed traditional trial comparing the same treatments within the same pediatric health-system. After 8 weeks of open-label Advair 250/50 twice daily, participants in both trial types are randomized to Advair 250/50, Flovent 250, or Advair 100/50 given 1 inhalation twice daily. Study staff track time spent to determine study costs. RESULTS Participants have been enrolled in the streamlined and traditional trials and recruitment is ongoing. CONCLUSIONS This project will provide important information on both clinical and economic outcomes for a novel method of conducting clinical trials. The results will be broadly applicable to trials of other diseases.

A system for creating personalized synthetic voices

We will be demonstrating the ModelTalker Voice Creation System, which allows users to create a personalized synthetic voice with an unrestricted vocabulary. The system includes a tool for recording a speech inventory and a program that converts the recorded inventory into a synthetic voice for the ModelTalker TTS engine. The entire system can be downloaded for use on a home PC or in a clinical setting, and the resulting synthetic voices can be used with any SAPI compliant system.We will demonstrate the recording process, and convert the recordings to a mini-database with a limited vocabulary for participants to hear.

Using automatic alignment to analyze endangered language data: Testing the viability of untrained alignment

While efforts to document endangered languages have steadily increased, the phonetic analysis of endangered language data remains a challenge. The transcription of large documentation corpora is, by itself, a tremendous feat. Yet, the process of segmentation remains a bottleneck for research with data of this kind. This paper examines whether a speech processing tool, forced alignment, can facilitate the segmentation task for small data sets, even when the target language differs from the training language. The authors also examined whether a phone set with contextualization outperforms a more general one. The accuracy of two forced aligners trained on English (hmalign and p2fa) was assessed using corpus data from Yoloxóchitl Mixtec. Overall, agreement performance was relatively good, with accuracy at 70.9% within 30 ms for hmalign and 65.7% within 30 ms for p2fa. Segmental and tonal categories influenced accuracy as well. For instance, additional stop allophones in hmaligns phone set aided alignment accuracy. Agreement differences between aligners also corresponded closely with the types of data on which the aligners were trained. Overall, using existing alignment systems was found to have potential for making phonetic analysis of small corpora more efficient, with more allophonic phone sets providing better agreement than general ones.

ModelTalker Voice Recorder---An Interface System for Recording a Corpus of Speech for Synthesis

We will demonstrate the ModelTalker Voice Recorder (MT Voice Recorder) -- an interface system that lets individuals record and bank a speech database for the creation of a synthetic voice. The system guides users through an automatic calibration process that sets pitch, amplitude, and silence. The system then prompts users with both visual (text-based) and auditory prompts. Each recording is screened for pitch, amplitude and pronunciation and users are given immediate feedback on the acceptability of each recording. Users can then rerecord an unacceptable utterance. Recordings are automatically labeled and saved and a speech database is created from these recordings. The systems intention is to make the process of recording a corpus of utterances relatively easy for those inexperienced in linguistic analysis. Ultimately, the recorded corpus and the resulting speech database is used for concatenative synthetic speech, thus allowing individuals at home or in clinics to create a synthetic voice in their own voice. The interface may prove useful for other purposes as well. The system facilitates the recording and labeling of large corpora of speech, making it useful for speech and linguistic research, and it provides immediate feedback on pronunciation, thus making it useful as a clinical learning tool.

Using Markov models to assess articulation errors in young children

Digital recordings of children producing the names ‘‘Rhonda’’ and ‘‘Wanda,’’ and/or ‘‘Toto’’ and ‘‘Coco’’ were made using the microphone input to a Toshiba laptop computer (16‐bit samples, 22 050‐kHz sampling rate) with an AKG C410/B head‐mounted condenser microphone. These names were associated with animated characters in a mock video game running on the laptop under the control of a Speech Language Pathologist. The children, ranging in age from four to six years, were undergoing speech therapy at the Alfred I. duPont Hospital for Children for one or both of two common articulation errors: /w/ substituted for /r/; and/or /t/ substituted for /k/. The initial segment in each recorded utterance was classified by laboratory staff as either r/w or t/k, and assigned a goodness rating. Discrete Hidden Markov phoneme Models (DHMMs) trained using data recorded from normally articulating children were then used to classify the same utterances and results of the automatic classification were compared to the huma...

A cognitive approach for design of a multimedia informed consent video and website in pediatric research

OBJECTIVE Poor participant comprehension of research procedures following the conventional face-to-face consent process for biomedical research is common. We describe the development of a multimedia informed consent video and website that incorporates cognitive strategies to enhance comprehension of study related material directed to parents and adolescents. MATERIALS AND METHODS A multidisciplinary team was assembled for development of the video and website that included human subjects professionals; psychologist researchers; institutional video and web developers; bioinformaticians and programmers; and parent and adolescent stakeholders. Five learning strategies that included Sensory-Modality view, Coherence, Signaling, Redundancy, and Personalization were integrated into a 15-min video and website material that describes a clinical research trial. RESULTS A diverse team collaborated extensively over 15months to design and build a multimedia platform for obtaining parental permission and adolescent assent for participant in as asthma clinical trial. Examples of the learning principles included, having a narrator describe what was being viewed on the video (sensory-modality); eliminating unnecessary text and graphics (coherence); having the initial portion of the video explain the sections of the video to be viewed (signaling); avoiding simultaneous presentation of text and graphics (redundancy); and having a consistent narrator throughout the video (personalization). DISCUSSION Existing conventional and multimedia processes for obtaining research informed consent have not actively incorporated basic principles of human cognition and learning in the design and implementation of these processes. The present paper illustrates how this can be achieved, setting the stage for rigorous evaluation of potential benefits such as improved comprehension, satisfaction with the consent process, and completion of research objectives. CONCLUSION New consent strategies that have an integrated cognitive approach need to be developed and tested in controlled trials.

Piecewise Mixed Effects Model to Compare the Weight-gain Patter ns Before and After Diagnosis of Asthma in Children Younger than 5 Years.

Asthma and obesity are two significant public health problems that both originate in early childhood and have shared risk factors and manifestations. Studies suggest a strong association between asthma development and subsequent accelerated weight gain. Children are diagnosed with asthma in early childhood and are often exposed to factors associated with rapid weight gain. This article intends to demonstrate an innovative application of the piecewise mixed effects model to characterize the difference in the temporal rate of change in BMIz, the standardized scores of body mass index and weight-for-length that measure weight status, before and after asthma diagnosis in children younger than 5 years. The data consist of unique sequences from 1194 childrens clinic visits during the first 5 years of life. We used a knot at the time of diagnosis and detected a differential weight-gain pattern before and after asthma diagnosis. The pre- and post-asthma-diagnosis weight-gain patterns further differ by sex and race-ethnicity. After asthma diagnosis, female children showed a higher increase in the rate of change in BMIz than males. Non-Hispanic African Americans and Hispanics had higher post-diagnosis rates of change in BMIz than Caucasians. The differential weight-gain patterns between male and female children were mainly contributed by Caucasian children. These findings could have important implications in the clinical care of children after asthma diagnosis.