A User-Centered Design Approach to Developing a Voice Monitoring System for Disorder Prevention.

BACKGROUND: Many individuals will experience a voice disorder in their lifetime, especially occupational voice users. While a number of voice monitoring systems have been developed, most were designed with the clinician/researcher as the end user. For a patient to use these systems, they need field experts to help them interpret data from the system to understand its meaning. Most of these systems would have challenges in being used in a preventative context with the occupational voice user as the sole system user. OBJECTIVE: The current study introduces a novel design approach: user-centered design (UCD) with paper prototypes in the creation of a voice monitoring system for voice disorder prevention (VDP). The goal of this design approach is to design systems that are engaging and intuitive for users so they will be interested in interacting with the system and be able to benefit from the system without the need of external support. METHODS: The current study was conducted in two phases: an iterative design phase and a test phase. In the iterative design phase, 15 participants gave their opinions on the measures and feedback designs they felt would be the most beneficial to users. In the test phase, the researchers collected real voice data over multiple sessions for 18 additional participants and provided this data using the final feedback displays from the design phase. RESULTS: By engaging in UCD, the researchers identified key design challenges for VDP: (1) educating the user, (2) balancing contextualization and granularity, and (3) addressing disconnection between user and system goals. CONCLUSION: UCD holds promise for designing VDP systems that are both engaging and intuitive for occupational voice users.

Interactions Between Breathy and Rough Voice Qualities and Their Contributions to Overall Dysphonia Severity.

PURPOSE: Dysphonic voices typically present multiple voice quality dimensions. This study investigated potential interactions between perceived breathiness and roughness and their contributions to overall dysphonia severity. METHOD: Synthetic stimuli based on four talkers were created to systematically map out potential interactions. For each talker, a stimulus matrix composed of 49 stimuli (seven breathiness steps × seven roughness steps) was created by varying aspiration noise and open quotient to manipulate breathiness and superimposing amplitude modulation of varying depths to simulate roughness. One-dimensional matching (1DMA) and magnitude estimation (1DME) tasks were used to measure perceived breathiness, roughness, their potential interactions, and overall dysphonia severity. Additional 1DME tasks were used to assess a set of natural stimuli that varied along both breathiness and roughness. RESULTS: For the synthetic stimuli, the 1DMA task indicated little interaction between the two voice qualities. For the 1DME task, breathiness magnitude was influenced by roughness step to a greater extent than roughness magnitude was influenced by breathiness step. The additive contributions of breathiness and roughness to overall severity gradually diminished with increasing breathiness and roughness steps, possibly reflecting a ceiling effect in the 1DME task. For the natural stimuli, little consistent interaction was observed between breathiness and roughness. CONCLUSIONS: The matching task revealed minimal interaction between perceived breathiness and roughness, whereas the magnitude estimation task revealed some interaction between the two qualities and their cumulative contributions to overall dysphonia severity. Task differences are discussed in terms of differences in response bias and the role of perceptual anchors. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21313701.

Voice handicap Index in Parkinson's patients: Subthalamic versus globus pallidus deep brain stimulation.

PURPOSE: Subthalamic nucleus (STN) and globus pallidus interna (GPI) are the two most common sites for deep brain stimulation (DBS) in people with Parkinson's disease (PWP). Voice impairments are a common symptom of Parkinson's disease and information about voice outcomes with DBS is limited. Most studies in speech-language pathology have focused on STN-DBS and few have examined the effects of GPI-DBS. This was an initial effort to examine the impact of DBS location on Vocal Handicap Index (VHI) scores, which assess the impact of a voice disorder on an individual. METHOD: Twenty-four gender-matched PWP (12 STN-DBS and 12 GPI-DBS) completed the VHI post-DBS implantation. Two-tailed independent samples t-tests were used to compare each VHI scale score (physical, functional, emotional, total) and patient factors between the two groups. RESULTS: No significant differences in total or subscale VHI scores were identified between the two DBS groups. A trend toward greater impairment in PWP with GPI-DBS was noted. An association between higher VHI scores and DBS settings was found. CONCLUSIONS: Studies directly comparing speech outcomes for different DBS targets are lacking. The current findings provide new insights concerning voice outcomes following DBS by adding to the limited literature directly comparing speech outcomes in multiple DBS targets. Limitations and directions for future research are discussed.

Using Pitch Height and Pitch Strength to Characterize Type 1, 2, and 3 Voice Signals.

OBJECTIVE: Classifying dysphonic voices as type 1, 2, and 3 signals based on their periodicity enables researchers to determine the validity of acoustic measures derived from them. Existing methods of signal typing are commonly performed by listening to the voice sample and visualizing them on narrow-band spectrograms that require training, time, and are subjective in nature. The current study investigated pitch-based metrics (pitch height and pitch strength) as correlates to characterizing voice signal types. The computational estimates were validated with perceptual judgments of pitch height and pitch strength. METHODS: Pitch height and pitch strength were estimated from Auditory-Sawtooth Waveform Inspired Pitch Estimator Prime algorithm for 30 dysphonic voice segments (10 per type). Ten listeners evaluated pitch height through a single-variable matching task and pitch strength through an anchored magnitude estimation task. One way analyses of variance were used to determine the effects of signal type on pitch height and pitch strength estimates. Relationship between computational and perceptual estimates was evaluated using correlation coefficients and their significance. RESULTS: There was a significant difference between signal types in both computational and perceptual pitch strength estimates. Periodic type 1 signals had greater pitch strength compared to type 2 and 3 signals. Auditory-Sawtooth Waveform Inspired Pitch Estimator Prime produced robust computational estimates of pitch height even in type 3 signals when compared to other acoustic software. Listeners were able to reliably judge pitch height in type 2 and 3 signals despite their lack of a clear fundamental frequency. CONCLUSIONS: Pitch height and pitch strength can be measured in all dysphonic voices irrespective of signal periodicity.

The Perception of Breathiness in the Voices of Pediatric Speakers.

BACKGROUND: The perception of pediatric voice quality has been investigated using clinical protocols developed for adult voices and acoustic analyses designed to identify important physical parameters associated with normal and dysphonic pediatric voices. Laboratory investigations of adult dysphonia have included sophisticated methods, including a psychoacoustic approach that involves a single-variable matching task (SVMT), characterized by high inter- and intra-listener reliability, and analyses that include bio-inspired models of auditory perception that have provided valuable information regarding adult voice quality. OBJECTIVES: To establish the utility of a psychoacoustic approach to the investigation of voice quality perception in the context of pediatric voices? METHODS: Six listeners judged the breathiness of 20 synthetic vowel stimuli using an SVMT. To support comparisons with previous data, stimuli were modeled after four pediatric speakers and synthesized using Klatt with five parameter settings that influence the perception of breathiness. The population average breathiness judgments were modeled with acoustic measures of loudness ratio, pitch strength, and cepstral peak. RESULTS: Listeners reliably judged the perceived breathiness of pediatric voices, as with previous investigations of breathiness in adult dysphonic voices. Breathiness judgments were accurately modeled by loudness ratio (r2 = 0.93), pitch strength (r2 = 0.91), and cepstral peak (r2 = 0.82). Model accuracy was not affected significantly by including stimulus fundamental frequency and was slightly higher for pediatric than for adult voices. CONCLUSIONS: The SVMT proved robust for pediatric voices spanning a wide range of breathiness. The data indicate that this is a promising approach for future investigation of pediatric voice quality.

Comparison of Pitch Strength With Perceptual and Other Acoustic Metric Outcome Measures Following Medialization Laryngoplasty.

INTRODUCTION: The diagnoses of voice disorders, as well as treatment outcomes, are often tracked using visual (eg, stroboscopic images), auditory (eg, perceptual ratings), objective (eg, from acoustic or aerodynamic signals), and patient report (eg, Voice Handicap Index and Voice-Related Quality of Life) measures. However, many of these measures are known to have low to moderate sensitivity and specificity for detecting changes in vocal characteristics, including vocal quality. OBJECTIVE: The objective of this study was to compare changes in estimated pitch strength (PS) with other conventionally used acoustic measures based on the cepstral peak prominence (smoothed cepstral peak prominence, cepstral spectral index of dysphonia, and acoustic voice quality index), and clinical judgments of voice quality (GRBAS [grade, roughness, breathiness, asthenia, strain] scale) following laryngeal framework surgery. METHODS: This study involved post hoc analysis of recordings from 22 patients pretreatment and post treatment (thyroplasty and behavioral therapy). Sustained vowels and connected speech were analyzed using objective measures (PS, smoothed cepstral peak prominence, cepstral spectral index of dysphonia, and acoustic voice quality index), and these results were compared with mean auditory-perceptual ratings by expert clinicians using the GRBAS scale. RESULTS: All four acoustic measures changed significantly in the direction that usually indicates improved voice quality following treatment (P < 0.005). Grade and breathiness correlated the strongest with the acoustic measures (|r| ~ 0.7) with strain being the least correlated. CONCLUSIONS: Acoustic analysis on running speech highly correlates with judged ratings. PS is a robust, easily obtained acoustic measure of voice quality that could be useful in the clinical environment to follow treatment of voice disorders.

Objective Indices of Perceived Vocal Strain.

BACKGROUND: A limited number of experiments have investigated the perception of strain compared to the voice qualities of breathiness and roughness despite its widespread occurrence in patients who have hyperfunctional voice disorders, adductor spasmodic dysphonia, and vocal fold paralysis among others. OBJECTIVE: The purpose of this study is to determine the perceptual basis of strain through identification and exploration of acoustic and psychoacoustic measures. METHODS: Twelve listeners evaluated the degree of strain for 28 dysphonic phonation samples on a five-point rating scale task. Computational estimates based on cepstrum, sharpness, and spectral moments (linear and transformed with auditory processing front-end) were correlated to the perceptual ratings. RESULTS: Perceived strain was strongly correlated with cepstral peak prominence, sharpness, and a subset of the spectral metrics. Spectral energy distribution measures from the output of an auditory processing front-end (ie, excitation pattern and specific loudness pattern) accounted for 77-79% of the model variance for strained voices in combination with the cepstral measure. CONCLUSIONS: Modeling the perception of strain using an auditory front-end prior to acoustic analysis provides better characterization of the perceptual ratings of strain, similar to our prior work on breathiness and roughness. Results also provide evidence that the sharpness model of Fastl and Zwicker (2007) is one of the strong predictors of strain perception.

Pitch Strength as an Outcome Measure for Treatment of Dysphonia.

BACKGROUND: Measurement of treatment outcomes is critical for the spectrum of voice treatments (ie, surgical, behavioral, or pharmacological). Outcome measures typically include visual (eg, stroboscopic data), auditory (eg, Consensus Auditory-Perceptual Evaluation of Voice; Grade, Roughness, Breathiness, Asthenia, Strain), and objective correlates of vocal fold vibratory characteristics, such as acoustic signals (eg, harmonics-to-noise ratio, cepstral peak prominence) or patient self-reported questionnaires (eg, Voice Handicap Index, Voice-Related Quality of Life). Subjective measures often show high variability, whereas most acoustic measures of voice are only valid for signals where some degree of periodicity can be assumed. However, this assumption is often invalid for dysphonic voices where signal periodicity is suspect. Furthermore, many of these measures are not useful in isolation for diagnostic purposes. OBJECTIVE: We evaluated a recently developed algorithm (Auditory Sawtooth Waveform Inspired Pitch Estimator-Prime [Auditory-SWIPE']) for estimating pitch and pitch strength for dysphonic voices. Whereas fundamental frequency is a physical attribute of a signal, pitch is its psychophysical correlate. As such, the perception of pitch can extend to most signals irrespective of their periodicity. METHODS: Post hoc analyses were conducted for three groups of patients evaluated and treated for voice problems at a major voice center: (1) muscle tension dysphonia/functional dysphonia, (2) vocal fold mass(es), and (3) presbyphonia. All patients were recorded before and after surgical/behavioral treatment for voice disorders. Pitch and pitch strength for each speaker were computed with the Auditory-SWIPE' algorithm. RESULTS: Comparison of pre- and posttreatment data provides support for pitch strength as a measure of treatment outcomes for dysphonic voices.

The psychophysics of roughness applied to dysphonic voice.

Roughness is a sound quality that has been related to the amplitude modulation characteristics of the acoustic stimulus. Roughness also is considered one of the primary elements of voice quality associated with natural variations across normal voices and is a salient feature of many dysphonic voices. It is known that the roughness of tonal stimuli is dependent on the frequency and depth of amplitude modulation and on the carrier frequency. Here, it is determined if similar dependencies exist for voiced speech stimuli. Knowledge of such dependencies can lead to a better understanding of the acoustic characteristics of vocal roughness along the continuum of normal to dysphonic and may facilitate computational estimates of vocal roughness. Synthetic vowel stimuli were modeled after talkers selected from the Satloff/Heman-Ackah disordered voice database. To parametrically control amplitude modulation frequency and depth, synthesized stimuli had minimal amplitude fluctuations, and amplitude modulation was superimposed with the desired frequency and depth. Perceptual roughness judgments depended on amplitude modulation frequency and depth in a manner that closely matched data from tonal carriers. The dependence of perceived roughness on amplitude modulation frequency and depth closely matched the roughness of sinusoidal carriers as reported by Fastl and Zwicker [(2007) Psychoacoustics: Facts and Models, 3rd ed. (Springer, New York)].

Videos Influence Behavior Change Measures for Voice and Speech in Individuals with Parkinson's Disease.

The majority of individuals with Parkinson's disease (PD) experience voice and speech difficulties at some point over the course of the disease. Voice therapy has been found to help improve voice and speech in individuals with PD, but the majority of these individuals do not enroll in voice therapy. The purpose of this study was to determine whether watching short videos about voice symptoms and treatment in Parkinson's disease influences readiness to change, stages of change, and self-efficacy in individuals with PD. Eight individuals with PD participated in the study. Fifteen videos were chosen, three representing each of the five stages of change. We chose videos from YouTube that represented variety in speakers, content, and genre. We found that readiness to change significantly increased after watching videos, suggesting that watching videos helped these individuals move closer to actively improving their voice and speech. In addition, five of the eight participants showed forward movement in stages of change. Finally, self-efficacy demonstrated a positive trend following video watching. Overall, our results demonstrate that watching videos available on the internet can influence individuals with Parkinson's disease in changing vocal behavior. Implications for future wireless health applications are described.