Validity of Acoustic Measures Obtained Using Various Recording Methods Including Smartphones With and Without Headset Microphones

PURPOSE

The goal of this study was to assess various recording methods, including combinations of high- versus low-cost microphones, recording interfaces, and smartphones in terms of their ability to produce commonly used time- and spectral-based voice measurements.

METHOD

Twenty-four vowel samples representing a diversity of voice quality deviations and severities from a wide age range of male and female speakers were played via a head-and-thorax model and recorded using a high-cost, research standard GRAS 40AF (GRAS Sound & Vibration) microphone and amplification system. Additional recordings were made using various combinations of headset microphones (AKG C555 L [AKG Acoustics GmbH], Shure SM35-XLR [Shure Incorporated], AVID AE-36 [AVID Products, Inc.]) and audio interfaces (Focusrite Scarlett 2i2 [Focusrite Audio Engineering Ltd.] and PC, Focusrite and smartphone, smartphone via a TRRS adapter), as well as smartphones direct (Apple iPhone 13 Pro, Google Pixel 6) using their built-in microphones. The effect of background noise from four different room conditions was also evaluated. Vowel samples were analyzed for measures of fundamental frequency, perturbation, cepstral peak prominence, and spectral tilt (low vs. high spectral ratio).

RESULTS

Results show that a wide variety of recording methods, including smartphones with and without a low-cost headset microphone, can effectively track the wide range of acoustic characteristics in a diverse set of typical and disordered voice samples. Although significant differences in acoustic measures of voice may be observed, the presence of extremely strong correlations (rs > .90) with the recording standard implies a strong linear relationship between the results of different methods that may be used to predict and adjust any observed differences in measurement results.

CONCLUSION

Because handheld smartphone distance and positioning may be highly variable when used in actual clinical recording situations, smartphone + a low-cost headset microphone is recommended as an affordable recording method that controls mouth-to-microphone distance and positioning and allows both hands to be available for manipulation of the smartphone device.

Plug-and-Play Microphones for Recording Speech and Voice with Smart Devices

INTRODUCTION

Smart devices are widely available and capable of quickly recording and uploading speech segments for health-related analysis. The switch from laboratory recordings with professional-grade microphone setups to remote, smart device-based recordings offers immense potential for the scalability of voice assessment. Yet, a growing body of literature points to a wide heterogeneity among acoustic metrics for their robustness to variation in recording devices. The addition of consumer-grade plug-and-play microphones has been proposed as a possible solution. The aim of our study was to assess if the addition of consumer-grade plug-and-play microphones increases the acoustic measurement agreement between ultra-portable devices and a reference microphone.

METHODS

Speech was simultaneously recorded by a reference high-quality microphone commonly used in research and by two configurations with plug-and-play microphones. Twelve speech-acoustic features were calculated using recordings from each microphone to determine the agreement intervals in measurements between microphones. Agreement intervals were then compared to expected deviations in speech in various neurological conditions. Each microphone's response to speech and to silence was characterized through acoustic analysis to explore possible reasons for differences in acoustic measurements between microphones. The statistical differentiation of two groups, neurotypical and people with multiple sclerosis, using metrics from each tested microphone was compared to that of the reference microphone.

RESULTS

The two consumer-grade plug-and-play microphones favored high frequencies (mean center of gravity difference ≥ +175.3 Hz) and recorded more noise (mean difference in signal to noise ≤ -4.2 dB) when compared to the reference microphone. Between consumer-grade microphones, differences in relative noise were closely related to distance between the microphone and the speaker's mouth. Agreement intervals between the reference and consumer-grade microphones remained under disease-expected deviations only for fundamental frequency (f0, agreement interval ≤0.06 Hz), f0 instability (f0 CoV, agreement interval ≤0.05%), and tracking of second formant movement (agreement interval ≤1.4 Hz/ms). Agreement between microphones was poor for other metrics, particularly for fine timing metrics (mean pause length and pause length variability for various tasks). The statistical difference between the two groups of speakers was smaller with the plug-and-play than with the reference microphone.

CONCLUSION

Measurement of f0 and F2 slope was robust to variation in recording equipment, while other acoustic metrics were not. Thus, the tested plug-and-play microphones should not be used interchangeably with professional-grade microphones for speech analysis. Plug-and-play microphones may assist in equipment standardization within speech studies, including remote or self-recording, possibly with small loss in accuracy and statistical power as observed in the current study.

Voice Use in Daily Life Studied With a Portable Voice Accumulator in Individuals With Parkinson's Disease and Matched Healthy Controls

Purpose The purpose of this work was to study how voice use in daily life is impacted by Parkinson's disease (PD), specifically if there is a difference in voice sound level and phonation ratio during everyday activities for individuals with PD and matched healthy controls. A further aim was to study how variations in environmental noise impact voice use. Method Long-term registration of voice use during 1 week in daily life was performed for 21 participants with PD (11 male, 10 female) and 21 matched healthy controls using the portable voice accumulator VoxLog. Voice use was assessed through registrations of spontaneous speech in different ranges of environmental noise in daily life and in a controlled studio recording setting. Results Individuals with PD use their voice 50%-60% less than their matched healthy controls in daily life. The difference increases in high levels of environmental noise. Individuals with PD used an average voice sound level in daily life that was 8.11 dB (female) and 6.7 dB (male) lower than their matched healthy controls. Difference in mean voice sound level for individuals with PD and controls during spontaneous speech during a controlled studio registration was 3.0 dB for the female group and 4.1 dB for the male group. Conclusions The observed difference in voice use in daily life between individuals with PD and matched healthy controls is a 1st step to objectively quantify the impact of PD on communicative participation. The variations in voice use in different levels of environmental noise and when comparing controlled and variable environments support the idea that the study of voice use should include methods to assess function in less controlled situations outside the clinical setting.

Simultaneous electromagnetic articulography and electroglottography data acquisition of natural speech

This paper reports on the concurrent use of electroglottography (EGG) and electromagnetic articulography (EMA) in the acquisition of EMA trajectory data for running speech. Static and dynamic intersensor distances, standard deviations, and coefficients of variation associated with inter-sample distances were compared in two conditions: with and without EGG present. Results indicate that measurement discrepancies between the two conditions are within the EMA system's measurement uncertainty. Therefore, potential electromagnetic interference from EGG does not seem to cause differences of practical importance on EMA trajectory behaviors, suggesting that simultaneous EMA and EGG data acquisition is a viable laboratory procedure for speech research.

Articulatory, acoustic, and prosodic accommodation in a cooperative maze navigation task

This study uses a maze navigation task in conjunction with a quasi-scripted, prosodically controlled speech task to examine acoustic and articulatory accommodation in pairs of interacting speakers. The experiment uses a dual electromagnetic articulography set-up to collect synchronized acoustic and articulatory kinematic data from two facing speakers simultaneously. We measure the members of a dyad individually before they interact, while they are interacting in a cooperative task, and again individually after they interact. The design is ideally suited to measure speech convergence, divergence, and persistence effects during and after speaker interaction. This study specifically examines how convergence and divergence effects during a dyadic interaction may be related to prosodically salient positions, such as preceding a phrase boundary. The findings of accommodation in fine-grained prosodic measures illuminate our understanding of how the realization of linguistic phrasal structure is coordinated across interacting speakers. Our findings on individual speaker variability and the time course of accommodation provide novel evidence for accommodation at the level of cognitively specified motor control of individual articulatory gestures. Taken together, these results have implications for understanding the cognitive control of interactional behavior in spoken language communication.

Uncertainty of speech level parameters measured with a contact-sensor-based device and a headworn microphone

This work estimates the uncertainty contributions of speech level parameters measured with a contact-sensor-based device and a headworn microphone. Four contributions are considered: (1) instrumental uncertainty, related to device calibration; (2) method repeatability and (3) reproducibility, estimated through repeated measurements without and with device repositioning, respectively; (4) source reproducibility, due to the variability of human speech. To ascertain changes in speech production, differences between measures should be at least higher than the expanded uncertainty. In the case of device repositioning, the expanded uncertainty combines contributions (1), (3), and (4). When the device is not repositioned, it combines contributions (2) and (4).

Automated Language Environment Analysis: A Research Synthesis

PURPOSE

The Language Environment Analysis (LENA®) represents a breakthrough in automatic speech detection because it makes one's language environment, what adults and children actually hear and say, efficiently measurable. The purpose of this article was to examine (a) current dimensions of LENA research, (b) LENA's sensitivity to differences in populations and language environments, and (c) what has been achieved in closing the Word Gap.

METHOD

From electronic and human searches, 83 peer-reviewed articles using LENA were identified, and 53 met inclusionary criteria and were included in a systematic literature review. Each article reported results of 1 study.

RESULTS

Originally developed to make natural language research more efficient and feasible, systematic review identified a broad landscape of relevant LENA findings focused primarily on the environments and communications of young children but also older adults and teachers. LENA's automated speech indicators (adult input, adult-child interaction, and child production) and the audio environment were shown to meet high validity standards, including accuracy, sensitivity to individual differences, and differences in populations, settings, contexts within settings, speakers, and languages. Researchers' own analyses of LENA audio recordings have extended our knowledge of microlevel processes in adult-child interaction. To date, intervention research using LENA has consisted of small pilot experiments, primarily on the effects of brief parent education plus quantitative linguistic feedback to parents.

CONCLUSION

Evidence showed that automated analysis has made a place in the repertoire of language research and practice. Implications, limitations, and future research are discussed.

Using ultrasound and nasalance to separate oral and nasal contributions to formant frequencies of nasalized vowels

The experimental method described in this manuscript offers a possible means to address a well known issue in research on the independent effects of nasalization on vowel acoustics: given that the separate transfer functions associated with the oral and nasal cavities are merged in the acoustic signal, the task of teasing apart the respective effects of the two cavities seems to be an intractable problem. The proposed method uses ultrasound and nasalance to predict the effect of lingual configuration on formant frequencies of nasalized vowels, thus accounting for acoustic variation due to changing lingual posture and excluding its contribution to the acoustic signal. The results reveal that the independent effect of nasalization on the acoustic vowel quadrilateral resembles a counter-clockwise chain shift of nasal compared to non-nasal vowels. The results from the productions of 11 vowels by six speakers of different language backgrounds are compared to predictions presented in previous modeling studies, as well as discussed in the light of sound change of nasal vowel systems.

Tutorial and Guidelines on Measurement of Sound Pressure Level in Voice and Speech

PURPOSE

Sound pressure level (SPL) measurement of voice and speech is often considered a trivial matter, but the measured levels are often reported incorrectly or incompletely, making them difficult to compare among various studies. This article aims at explaining the fundamental principles behind these measurements and providing guidelines to improve their accuracy and reproducibility.

METHOD

Basic information is put together from standards, technical, voice and speech literature, and practical experience of the authors and is explained for nontechnical readers.

RESULTS

Variation of SPL with distance, sound level meters and their accuracy, frequency and time weightings, and background noise topics are reviewed. Several calibration procedures for SPL measurements are described for stand-mounted and head-mounted microphones.

CONCLUSIONS

SPL of voice and speech should be reported together with the mouth-to-microphone distance so that the levels can be related to vocal power. Sound level measurement settings (i.e., frequency weighting and time weighting/averaging) should always be specified. Classified sound level meters should be used to assure measurement accuracy. Head-mounted microphones placed at the proximity of the mouth improve signal-to-noise ratio and can be taken advantage of for voice SPL measurements when calibrated. Background noise levels should be reported besides the sound levels of voice and speech.

Accuracy of the quantities measured by four vocal dosimeters and its uncertainty

Although vocal dosimeters are often used for long-term voice monitoring, the uncertainty of the quantities measured by these devices is not always stated. In this study, two common vocal dosimetry quantities, mean vocal sound pressure level and mean vocal fundamental frequency, were measured by four vocal dosimeters (VocaLog2, VoxLog, Voice Care, and APM3200). The expanded uncertainty of the mean error in the estimation of these two quantities as measured by the four dosimeters was performed by simultaneously comparing signals acquired through a reference microphone and the devices themselves. Dosimeters, assigned in random order, were worn by the participants (22 vocally healthy adults), along with a head-mounted microphone, which acted as a reference. For each device, participants produced a sustained /a/ vowel four times and then read a text with three different vocal efforts (relaxed, normal, and raised). The measurement uncertainty was obtained by comparing data from the microphone and the dosimeters. The mean vocal sound pressure level was captured the most accurately by the Voice Care and the VoxLog while the APM3200 was the least accurate. The most accurate mean vocal fundamental frequency was estimated by the Voice Care and the APM3200, while the VoxLog was the least accurate.

Acoustic Analysis of Voice in Singers: A Systematic Review

PURPOSE

Singers are vocal athletes having specific demands from their voice and require special consideration during voice evaluation. Presently, there is a lack of standards for acoustic evaluation in them. The aim of the present study was to systematically review the available literature on the acoustic analysis of voice in singers.

METHOD

A systematic review of studies on acoustic analysis of voice in singers (PubMed/MEDLINE, CINAHL, Scopus, ProQuest, Cochrane, Ovid, Science Direct, and Shodhganga) was carried out. Key words based on PIO (population-investigation-outcome) were used to develop search strings. Titles and abstracts were screened independently, and appropriate studies were read in full for data extraction.

RESULTS

Of the 895 studies, 26 studies met the inclusion criteria. Great variability was noted in the instruments and task used. Different acoustic measures were employed, such as fundamental frequency, perturbation, cepstral, spectral, dysphonia severity index, singing power ratio, and so forth.

CONCLUSION

Overall, a great heterogeneity was noted regarding population, tasks, instruments, and parameters. There is a lack of standardized criteria for the evaluation of singing voice. In order to implement acoustic analysis as a part of comprehensive voice evaluation exclusively for singers, there is a certain need for methodical sound studies.

Test-Retest Nasalance Score Variability in Hypernasal Speakers

Objective

The objective of this study was to evaluate test-retest nasalance score variability in subjects with hypernasal resonance.

Design

Two groups of subjects with hypernasal speech recited both the Turtle Passage and the Mouse Passage two times each. For one group, the Nasometer headgear was not changed between repetitions of each stimulus (NCHG; n = 17); and for the other group, the headgear was changed between repetitions (CHG; n = 18). Three subjects in the CHG group would not recite the Mouse Passage two times.

Participants

The subjects were 35 patients with hypernasal speech followed by a cleft palate team.

Main Outcome Measures

The outcome measures were the four nasalance scores obtained for each subject.

Results

There was no significant difference between first and second repetitions for either stimulus in either the NCHG group or in the CHG group. Cumulative frequency tables showed that for the Turtle Passage-NCHG condition, 15 of the 17 (88%) repeated nasalance scores were within 5 nasalance points of each other. For the CHG condition, however, only 9 of 18 (50%) repeated nasalance scores were within 5 points. For the Mouse Passage-NCHG condition, 15 of the 17 (88%) repeated nasalance scores were within 5 points. For the CHG condition, however, only 11 of 15 (73%) repeated scores were within 5 points.

Conclusions

Test-retest variability was greater in a population of hypernasal patients than that reported in other studies for normal speakers, and headgear change increased test-retest variability.

Validity of the Nasometer Measuring the Temporal Characteristics of Nasalization

Objective:

To examine the validity of the Nasometer (KayPENTAX, Lincoln Park, NJ) in measuring the temporal characteristics of nasalization by comparing the Nasometer measures to the measures from an external criterion procedure.

Design:

Speech samples consisted of three rate-controlled nonsense syllables, which varied in their vowel compositions: /izinizi/, /azanaza/, and /uzunuzu/. Acoustic data were recorded simultaneously through the Nasometer and an external criterion procedure (a specialized microphone set that collected acoustic signals separately for the nasal and oral channels). Speech segment durations measured from the two instrumental conditions were compared on the Nasometer display and the Computerized Speech Lab (KayPENTAX, Lincoln Park, NJ) display. Five durational variables were measured: total utterance duration, nasal onset interval, nasal consonant duration, nasal offset interval, and total nasalization duration.

Participants:

Fourteen normal adults who speak American English as their first language participated in the study.

Results:

No significant differences were found between the measures from the Nasometer and those from an external criterion procedure in all the durational variables pertinent to nasalization. Different vowels, however, yielded significantly different patterns in these durational variables, in which the low vowel /a/ context revealed significantly longer total nasalization duration than did the high vowel /i/ and /u/ contexts.

Conclusions:

The results suggest that the Nasometer can be used as a valid tool to measure the temporal characteristics underlying nasalization and confirm significant vowel effects on the temporal patterns of nasalization.

Comparison of Nasalance Scores Obtained with the Nasometer, the NasalView, and the OroNasal System

Objective

To compare nasalance scores obtained with the Nasometer, the NasalView, and the OroNasal System; evaluate test-retest reliability of the three systems; and explore whether three common text passages used for nasalance analysis could be shortened to a sentence each.

Subjects

Seventy-six adults with normal speech and hearing (mean age 26.5 years).

Procedures

Subjects read the complete Zoo Passage, Rainbow Passage, and Nasal Sentences.

Main Outcome Measures

Mean nasalance magnitudes and mean nasalance distances were obtained with the three devices.

Results

The Nasometer had the lowest nasalance scores for the nonnasal Zoo Passage. The NasalView had the highest nasalance scores for the phonetically balanced Rainbow Passage. The OroNasal System had the lowest nasalance scores for the Nasal Sentences. The nasalance distance was largest for the Nasometer and smallest for the OroNasal System. Over 90% of the recordings were within 4% to 6% nasalance for most materials recorded with the Nasometer and the NasalView and within 7% to 9% for materials recorded with the OroNasal System. There were significant differences between the complete Zoo Passage and the Nasal Sentences and the individual sentences from these passages for the Nasometer and the OroNasal System.

Conclusions

The three systems measure nasalance in different ways and provide nasalance scores that are not interchangeable. Test-retest variability for the Nasometer and the NasalView may be higher than previously reported. Individual sentences from the Zoo Passage and the Nasal Sentences do not provide nasalance scores that are equivalent to the complete passages.

Nasalance Scores for Normal-Speaking Irish Children

Objective

To obtain normal nasalance values during the production of a standardized speech sample for Irish children and determine whether significantly different scores exist for different speech stimuli for female and male speakers.

Design

Mean nasalance scores were obtained for normal-speaking children during the repetition of 16 test sentences that were categorized according to consonant type within the sentences (high-pressure consonants, low-pressure consonants, nasal consonants).

Participants

Seventy children (36 girls and 34 boys, aged 4 years 11 months to 13 years) with normal articulation, resonance, and voice were included.

Procedures

Children repeated each of the 16 test sentences individually. The sentences were presented in groups according to consonant type, referred to as sentence categories. Data were collected and analyzed using the Kay nasometer (model 6200.3). Nasalance scores were obtained for the total speech sample and each sentence category. Data were statistically analyzed to investigate the effects of gender, sentence category, and gender by sentence category.

Results

Normative nasalance scores were obtained for the total speech sample (26%), high-pressure consonant sentences (14%), low-pressure consonant sentences (16%), and a nasal consonant sentence (51%). There was no significant difference in nasalance scores between male and female speakers. Significant differences were found between each sentence category (p ≤ .001), except between the high-pressure and low-pressure consonant sentence categories (p = .09).

Conclusion

The present study provides normative nasalance data for English-speaking Irish children. There was a significant difference between nasalance scores for different speech stimuli.

A Comparative Study of the Precision of Carstens and Northern Digital Instruments Electromagnetic Articulographs

PURPOSE

This study compares the precision of the electromagnetic articulographs used in speech research: Northern Digital Instruments' Wave and Carstens' AG200, AG500, and AG501 systems.

METHOD

The fluctuation of distances between 3 pairs of sensors attached to a manually rotated device that can position them inside the measurement volumes was determined. For each device, 2 precision estimates made on the basis of the 95% quantile range of these distances (QR95) were defined: The local QR95 was computed for bins around specific rotation angles, and the global QR95 was computed for all angles pooled.

RESULTS

For all devices, although the local precision lies around 0.1 cm, the global precision is much more worrisome, ranging from 0.03 cm to 2.18 cm, and displays large variations as a function of the position of the sensors in the measurement volume. No influence of the rotational speed was found. The AG501 produced-by far-the lowest errors, in particular concerning the global precision.

CONCLUSIONS

The local precision can be considered suitable for speech articulatory measurements, but the variations of the global precision need to be taken into account by the knowledge of the spatial distribution of errors. A guideline for good practice in EMA recording is proposed for each system.

Real-Time Control of an Articulatory-Based Speech Synthesizer for Brain Computer Interfaces

Restoring natural speech in paralyzed and aphasic people could be achieved using a Brain-Computer Interface (BCI) controlling a speech synthesizer in real-time. To reach this goal, a prerequisite is to develop a speech synthesizer producing intelligible speech in real-time with a reasonable number of control parameters. We present here an articulatory-based speech synthesizer that can be controlled in real-time for future BCI applications. This synthesizer converts movements of the main speech articulators (tongue, jaw, velum, and lips) into intelligible speech. The articulatory-to-acoustic mapping is performed using a deep neural network (DNN) trained on electromagnetic articulography (EMA) data recorded on a reference speaker synchronously with the produced speech signal. This DNN is then used in both offline and online modes to map the position of sensors glued on different speech articulators into acoustic parameters that are further converted into an audio signal using a vocoder. In offline mode, highly intelligible speech could be obtained as assessed by perceptual evaluation performed by 12 listeners. Then, to anticipate future BCI applications, we further assessed the real-time control of the synthesizer by both the reference speaker and new speakers, in a closed-loop paradigm using EMA data recorded in real time. A short calibration period was used to compensate for differences in sensor positions and articulatory differences between new speakers and the reference speaker. We found that real-time synthesis of vowels and consonants was possible with good intelligibility. In conclusion, these results open to future speech BCI applications using such articulatory-based speech synthesizer.

Multimodal acquisition of articulatory data: Geometrical and temporal registration

Acquisition of dynamic articulatory data is of major importance for studying speech production. It turns out that one technique alone often is not enough to get a correct coverage of the whole vocal tract at a sufficient sampling rate. Ultrasound (US) imaging has been proposed as a good acquisition technique for the tongue surface because it offers a good temporal sampling, does not alter speech production, is cheap, and is widely available. However, it cannot be used alone and this paper describes a multimodal acquisition system which uses electromagnetography sensors to locate the US probe. The paper particularly focuses on the calibration of the US modality which is the key point of the system. This approach enables US data to be merged with other data. The use of the system is illustrated via an experiment consisting of measuring the minimal tongue to palate distance in order to evaluate and design Magnetic Resonance Imaging protocols well suited for the acquisition of three-dimensional images of the vocal tract. Compared to manual registration of acquisition modalities which is often used in acquisition of articulatory data, the approach presented relies on automatic techniques well founded from geometrical and mathematical points of view.

[The application of cybernetic modeling methods for the forensic medical personality identification based on the voice and sounding speech characteristics]

The objective of the present publication was to discuss the possibility of application of cybernetic modeling methods to overcome the apparent discrepancy between two kinds of the speech records, viz. initial ones (e.g. obtained in the course of special investigation activities) and the voice prints obtained from the persons subjected to the criminalistic examination. The paper is based on the literature sources and the materials of original criminalistics expertises performed by the authors.

Dialectical effects on nasalance: a multicenter, cross-continental study

PURPOSE

This study investigated nasalance in speakers from six different dialectal regions across North America using recent versions of the Nasometer. It was hypothesized that many of the sound changes observed in regional dialects of North American English would have a significant impact on measures of nasalance.

METHOD

Samples of the Zoo Passage, the Rainbow Passage, and the Nasal Sentences were collected from young adult male and female speakers (N=300) from six North American dialectical regions (Midland/Mid-Atlantic; Inland North Canada; Inland North; North Central; South; and Western dialects).

RESULTS

Across the three passage types, effect sizes for dialect were moderate in strength and accounted for approximately 7%-9% of the variation in nasalance. Increased differences in nasalance tended to occur between speakers from distinctly different geographical regions, with the highest nasalance across all passages observed for speakers from the Texas South dialect region.

CONCLUSION

Clinicians and researchers who use perceptual and instrumental measures of speech production should be aware that dialectical and socially acquired speech patterns may influence the acoustic characteristics of speech and may also influence the interpretation of normative expectations and typical versus disordered cutoff scores for instruments such as the Nasometer.

[Dynamic palatography: Diagnostic tool for dysfunc­tional swallowing? Feasibility study]

OBJECTIVE

Dysfunctional swallowing may cause transverse occlusal disorders. The speech re-education of dysfunctional swallowing aims to correct or prevent the recurrence of occlu­sal disorders. The main objective was to test the dynamic palato­graphy as a diagnosis and quantification tool of the dysfunctional swallowing.

MATERIAL AND METHODS

The study was prospective and descriptive. Twelve average 23.5 years old women with a clinical dysfunctional swallowing have been included between January and May 2014. None was aware of presenting an atypical swallowing or dento-facial dysmorphism of class II. The dynamic palatography device measured the pressure force of the language on the palate during the lingual rest, swallowing saliva and water. Parameters measured were the duration and magnitude of support of the tongue on the palate.

RESULTS

Dynamic palatography showed a trend to predominant anterior contact during rest position (25%), and lower position of the language with little contact during swallo­wing of saliva and water.

DISCUSSION

Palatography results are consistent with the clinical diagnostic criteria of atypical swallo­wing. Our palatography tool has the advantage of being unobtrusive in the mouth compared to other pre existing systems. This device should be tested on larger patient popu­la­tions and could enable monitore atypical swallowing rehabili­ta­tion efficiency. The palatography could complete the swallo­wing assessment and be a monitoring and rehabilitation tool in real time.

Automated analysis of child phonetic production using naturalistic recordings

PURPOSE

Conventional resource-intensive methods for child phonetic development studies are often impractical for sampling and analyzing child vocalizations in sufficient quantity. The purpose of this study was to provide new information on early language development by an automated analysis of child phonetic production using naturalistic recordings. The new approach was evaluated relative to conventional manual transcription methods. Its effectiveness was demonstrated by a case study with 106 children with typical development (TD) ages 8-48 months, 71 children with autism spectrum disorder (ASD) ages 16-48 months, and 49 children with language delay (LD) not related to ASD ages 10-44 months.

METHOD

A small digital recorder in the chest pocket of clothing captured full-day natural child vocalizations, which were automatically identified into consonant, vowel, nonspeech, and silence, producing the average count per utterance (ACPU) for consonant and vowel.

RESULTS

Clear child utterances were identified with above 72% accuracy. Correlations between machine-estimated and human-transcribed ACPUs were above 0.82. Children with TD produced significantly more consonants and vowels per utterance than did other children. Children with LD produced significantly more consonants but not vowels than did children with ASD.

CONCLUSION

The authors provide new information on typical and atypical language development in children with TD, ASD, and LD using an automated computational approach.

Real-time magnetic resonance imaging and electromagnetic articulography database for speech production research (TC)

USC-TIMIT is an extensive database of multimodal speech production data, developed to complement existing resources available to the speech research community and with the intention of being continuously refined and augmented. The database currently includes real-time magnetic resonance imaging data from five male and five female speakers of American English. Electromagnetic articulography data have also been presently collected from four of these speakers. The two modalities were recorded in two independent sessions while the subjects produced the same 460 sentence corpus used previously in the MOCHA-TIMIT database. In both cases the audio signal was recorded and synchronized with the articulatory data. The database and companion software are freely available to the research community.

Systematic studies of modified vocalization: the effect of speech rate on speech production measures during metronome-paced speech in persons who stutter

BACKGROUND

Metronome-paced speech results in the elimination, or substantial reduction, of stuttering moments. The cause of fluency during this fluency-inducing condition is unknown. Several investigations have reported changes in speech pattern characteristics from a control condition to a metronome-paced speech condition, but failure to control speech rate between conditions limits our ability to determine if the changes were necessary for fluency.

AIMS

This study examined the effect of speech rate on several speech production variables during one-syllable-per-beat metronomic speech in order to determine changes that may be important for fluency during this fluency-inducing condition.

METHODS & PROCEDURES

Thirteen persons who stutter (PWS), aged 18-62 years, completed a series of speaking tasks. Several speech production variables were compared between conditions produced at different metronome beat rates, and between a control condition and a metronome-paced speech condition produced at a rate equal to the control condition.

OUTCOMES & RESULTS

Vowel duration, voice onset time, pressure rise time and phonated intervals were significantly impacted by metronome beat rate. Voice onset time and the percentage of short (30-100 ms) phonated intervals significantly decreased from the control condition to the equivalent rate metronome-paced speech condition.

CONCLUSIONS & IMPLICATIONS

A reduction in the percentage of short phonated intervals may be important for fluency during syllable-based metronome-paced speech for PWS. Future studies should continue examining the necessity of this reduction. In addition, speech rate must be controlled in future fluency-inducing condition studies, including neuroimaging investigations, in order for this research to make a substantial contribution to finding the fluency-inducing mechanism of fluency-inducing conditions.

A dual-mode human computer interface combining speech and tongue motion for people with severe disabilities

We are presenting a new wireless and wearable human computer interface called the dual-mode Tongue Drive System (dTDS), which is designed to allow people with severe disabilities to use computers more effectively with increased speed, flexibility, usability, and independence through their tongue motion and speech. The dTDS detects users' tongue motion using a magnetic tracer and an array of magnetic sensors embedded in a compact and ergonomic wireless headset. It also captures the users' voice wirelessly using a small microphone embedded in the same headset. Preliminary evaluation results based on 14 able-bodied subjects and three individuals with high level spinal cord injuries at level C3-C5 indicated that the dTDS headset, combined with a commercially available speech recognition (SR) software, can provide end users with significantly higher performance than either unimodal forms based on the tongue motion or speech alone, particularly in completing tasks that require both pointing and text entry.