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.

The Influence of Multisensory Input On Voice Perception and Production Using Immersive Virtual Reality.

OBJECTIVES: The purpose was to examine the influence of auditory vs visual vs combined audiovisual input on perception and production of one's own voice, using immersive virtual reality technology. METHODS: Thirty-one vocally healthy men and women were investigated under 18 sensory input conditions, using immersive virtual reality technology. Conditions included two auditory rooms with varying reverberation times, two visual rooms with varying volumes, and the combination of audiovisual conditions. All conditions were repeated with and without background noise. Speech tasks included counting, sustained vowel phonation, an all-voiced sentence from the Consensus Auditory-Perceptual Evaluation of Voice, and the first sentence from the Rainbow Passage, randomly ordered. Perception outcome measures were participants' self-reported perceptions of their vocal loudness, vocal effort, and vocal comfort in speech. Production outcome measures were sound pressure level (SPL) and spectral moments (spectral mean and standard deviation in Hz, skewness, and kurtosis). Statistical analyses used self-reported vocal effort, vocal loudness, and vocal comfort in percent (0 = "not at all," 100 = extremely), SPL in dB, and spectral moments in Hz. The reference level was a baseline audiovisual deprivation condition. RESULTS: Results suggested (i) increased self-perceived vocal loudness and effort, and decreased comfort, with increasing room volume, speaker-to-listener distance, audiovisual input, and background noise, and (ii) increased SPL and fluctuations in spectral moments across conditions. CONCLUSIONS: Not only auditory, but also visual and audiovisual input influenced voice perception and production in ways that have not been previously documented. Findings contribute to the basic science understanding the role of visual, audiovisual and auditory input in voice perception and production, and also to models of voice training and therapy. The findings also set the foundation for the use of virtual reality in voice and speech training, as a potentially power solution to the generalization problem.

Smartphone Recordings are Comparable to "Gold Standard" Recordings for Acoustic Measurements of Voice.

PURPOSE: The purpose of this study was to assess the relationship and comparability of cepstral and spectral measures of voice obtained from a high-cost "flat" microphone and precision sound level meter (SLM) vs. high-end and entry level models of commonly and currently used smartphones (iPhone i12 and iSE; Samsung s21 and s9 smartphones). Device comparisons were also conducted in different settings (sound-treated booth vs. typical "quiet" office room) and at different mouth-to-microphone distances (15 and 30 cm). METHODS: The SLM and smartphone devices were used to record a series of speech and vowel samples from a prerecorded diverse set of 24 speakers representing a wide range of sex, age, fundamental frequency (F0), and voice quality types. Recordings were analyzed for the following measures: smoothed cepstral peak prominence (CPP in dB); the low vs high spectral ratio (L/H Ratio in dB); and the Cepstral Spectral Index of Dysphonia (CSID). RESULTS: A strong device effect was observed for L/H Ratio (dB) in both vowel and sentence contexts and for CSID in the sentence context. In contrast, device had a weak effect on CPP (dB), regardless of context. Recording distance was observed to have a small-to-moderate effect on measures of CPP and CSID but had a negligible effect on L/H Ratio. With the exception of L/H Ratio in the vowel context, setting was observed to have a strong effect on all three measures. While these aforementioned effects resulted in significant differences between measures obtained with SLM vs. smartphone devices, the intercorrelations of the measurements were extremely strong (r's > 0.90), indicating that all devices were able to capture the range of voice characteristics represented in the voice sample corpus. Regression modeling showed that acoustic measurements obtained from smartphone recordings could be successfully converted to comparable measurements obtained by a "gold standard" (precision SLM recordings conducted in a sound-treated booth at 15 cm) with small degrees of error. CONCLUSIONS: These findings indicate that a variety of commonly available modern smartphones can be used to collect high quality voice recordings usable for informative acoustic analysis. While device, setting, and distance can have significant effects on acoustic measurements, these effects are predictable and can be accounted for using regression modeling.

Comparative Analysis of Two Methods of Perceptual Voice Assessment.

OBJECTIVES: The primary aim was to compare two methods for perceptual evaluation of voice - paired comparison (PC) and visual analog scale (VAS) ratings. Secondary aims were to assess the correspondence between two dimensions of voice- overall severity of voice quality and resonant voice, and to investigate the influence of rater experience on perceptual rating scores and rating confidence scores. STUDY DESIGN: Experimental design. METHODS: Voice samples from six children (pre and post therapy) were rated by 15 Speech-Language Pathologists specialized in voice. Raters completed four tasks corresponding to the two rating methods and voice qualities: PC-severity, PC-resonance, VAS-severity, and VAS-resonance. For PC tasks, raters chose the better of two voice samples (better voice quality or better resonance, depending on the task) and indicated the degree of confidence in each choice. Rating and confidence score were combined to produce a number on a 1-10 scale (PC-confidence adjusted). VAS ratings involved rating voices on a scale for degree of severity and resonance, respectively. RESULTS: PC-confidence adjusted and VAS ratings were moderately correlated for overall severity and also vocal resonance. VAS ratings were normally distributed and had greater rater consistency than PC-confidence adjusted ratings. VAS scores reliably predicted binary PC choices (choice of voice sample only). Overall severity and vocal resonance were weakly correlated and rater experience was not linearly related to rating scores or confidence. CONCLUSIONS: Results suggest that the VAS rating method holds advantages over PC, including normally distributed ratings, superior consistency of ratings, and the ability to provide more finely grained detail regarding the auditory perception of voice. Overall severity and vocal resonance were not redundant in the current data set, suggesting that resonant voice and overall severity are not isomorphic. Finally, the number of years of clinical experience was not linearly related to perceptual ratings or rating confidence.

Investigation of the Cepstral Spectral Acoustic Analysis for Classifying the Severity of Dysphonia.

OBJECTIVES: The advantages of cepstral measurements in the evaluation of dysphonia have been noted in previous studies. However, there is an unclarity regarding the results of cepstral analyzes effect in determining the severity of dysphonia. The aims of this study were to determine the cut-off values of cepstral peak prominence, cepstral peak prominence standard deviation, low frequency/ high frequency ratio, low frequency/high frequency ratio standard deviation, and cepstral spectral index of dysphonia for predicting the voice severity within a Turkish speaking population, as well as to confirm the discriminative power of these cut-off values. MATERIALS METHODS: One hundred ninety-five individuals with voice disorders and an equal number of age and gender-matched individuals without voice disorders were included. Included subjects had visited the Hacettepe University Hospitals Speech and Language Therapy Department for voice evaluation between January 2017 and September 2021. The voice recordings from all participants included the six CAPE-V/Turkish sentences and sustained vowel /a/. Three raters provided auditory perceptual ratings of the voice samples using the GRBAS scale (grade) and overall severity for the CAPE-V/Turkish. Participants were categorized into normal and mild, moderate, and severely dysphonic groups based on the auditory perceptual evaluation. Analysis of Dysphonia in Speech and Voice (ADSV) software was used for cepstral spectral acoustic analysis. RESULTS: In the sustained vowel context, the area under the curve (ROC) for the CSID value was >0.8, except for mild vs. moderate dysphonia groups. In connected speech contexts, the ROC of the CPP value was also >0.8, except for normal vs. mild dysphonia groups. The cut-off values of CPP and CSID demonstrated high sensitivity and specificity for predicting voice severities. CONCLUSION: The cut-off values for the parameters that predicted voice severities showed a significant degree of discriminative power for categorizing voice severities among Turkish-speaking people.

Enhancing the Vortex Whistle for Measures of Respiratory Capacity Via Computational Fluid Dynamics and Computational Aero-Acoustic Analysis.

A vortex whistle produces a fundamental frequency proportional to the inlet flowrate. Recent investigations using vortex whistles have focused on the use of this relationship to quantify aspects of respiratory function. Despite promising results, there is a lack of understanding of the physical mechanisms underlying vortex whistle function. This paper begins with a principled study of the aero-acoustic properties of the vortex whistle. First, a high-fidelity computational fluid dynamics (CFD) simulation was developed to predict the unsteady flow field induced by the vortex whistle when the expiratory flow is applied. A computational aero-acoustic analysis (CAA) was applied to predict the acoustic response of the vortex whistle and to capture the frequency and level of the signature spectral peaks. The CFD is validated against prior experimental data on the vortex whistle. The CFD was used to: (a) determine the source of the vortex whistle harmonics and (b) investigate the effect of an outlet tube terminator, proposed by Awan and Awan (2020, "Use of a Vortex Whistle for Measures of Respiratory Capacity," J. Voice). The CFD and CAA indicated that the harmonics are generated by the cylindrical cavity of the vortex whistle, and the outlet terminator increases harmonic signal-to-noise ratio by increasing the pressure fluctuation within the cylindrical cavity. These results support the addition of the outlet tube terminator and provide insight into future design modifications that will enhance the reliability of the vortex whistle analyses and enable additional measures of respiratory capacity.

Clinician and Patient Perception of a Voice Therapy Program Utilizing a Variably Occluded Face Mask: A Pilot Study.

OBJECTIVE: The purpose of this investigation was to assess clinician and patient feedback about voice therapy using a variably occluded face mask (VOFM) and to determine if voice therapy augmented via a VOFM would result in favorable changes in patient self-perceived handicap, as well as acoustic and aerodynamic measures. METHODS/DESIGN: This pilot study used a prospective, pre-post single group design. Eleven patients with dysphonia due to primary muscle tension dysphonia (8) or benign vocal fold lesions (3) were recruited. Data collected included patient and clinician feedback of voice therapy using a VOFM, voice handicap index (VHI)-10, acoustic and aerodynamic measures. Data were collected before treatment (baseline) and 1-week post-therapy. Wilcoxon signed-rank tests were used to compare data pre- and post-therapy. RESULTS: Statistically significant improvement was observed for the VHI-10 with a median delta of -7. Clinician feedback generally reported that patients liked the VOFM, using the VOFM within the first two sessions of therapy, and within less than 10 min of use. All clinicians ranked the conversation level of the hierarchy as the most effective level. Three themes emerged from the Therapy Feedback Form: the VOFM was a (1) "Facilitator for Sensation," (2) a "Physical Tool," and that there was (3) "No Program Needed" to use the VOFM in voice therapy. There was a statistically significant improvement in cepstral peak prominence (p = 0.0329) and cepstral spectral index of dysphonia (p = 0.0164) in sustained vowels. DISCUSSION: This pilot study represents the first investigation into clinician and patient perceptions of using a VOFM. Reported measures via patient perception, as well as clinician perceptions, and some acoustic and aerodynamic measures showed that participants got better with VOFM voice therapy. Last, in general, both clinicians and patients liked utilizing a VOFM in voice therapy.

The Effect of Microphone Frequency Response on Spectral and Cepstral Measures of Voice: An Examination of Low-Cost Electret Headset Microphones.

PURPOSE: The purpose of this study was to establish the frequency response of a selection of low-cost headset microphones that could be given to subjects for remote voice recordings and to examine the effect of microphone type and frequency response on key acoustic measures related to voice quality obtained from speech and vowel samples. METHOD: The frequency responses of three low-cost headset microphones were evaluated using pink noise generated via a head-and-torso model. Each of the headset microphones was then used to record a series of speech and vowel samples prerecorded from 24 speakers who represented a diversity of sex, age, fundamental frequency (F o), and voice quality types. Recordings were later analyzed for the following measures: smoothed cepstral peak prominence (CPP; dB), low versus high spectral ratio (L/H ratio; dB), CPP F o (Hz), and cepstral spectral index of dysphonia (CSID). RESULTS: The frequency response of the microphones under test was observed to have nonsignificant effects on measures of the CPP and CPP F o, significant effects on the CSID in speech contexts, and strong and significant effects on the measure of spectral tilt (L/H ratio). However, the correlations between the various headset microphones and a reference precision microphone were excellent (rs > .90). CONCLUSIONS: The headset microphones under test all showed the capability to track a wide range of diversity in the voice signal. Though the use of higher quality microphones that have demonstrated specifications is recommended for typical research and clinical purposes, low-cost electret microphones may be used to provide valid measures of voice, specifically when the same microphone and signal chain is used for the evaluation of pre- versus posttreatment change or intergroup comparisons.

Use of a Vortex Whistle for Measures of Respiratory Capacity.

OBJECTIVES: A vortex whistle produces a tone which has a frequency proportional to the inlet air flow rate. The objectives of this study were to replicate previous studies demonstrating the use of a vortex whistle as an accurate flow meter, and to assess the degree of relationship between measures of vital capacity (VC) obtained using low-cost methods (vortex whistle and hand-held spirometry) vs. pneumotach-based spirometry. METHODOLOGY: A vortex whistle was designed using 3D modeling software and manufactured using a 3D printer with non-toxic, biodegradable polylactic acid (PLA). The digitized vortex whistle tone was analyzed using custom software to produce a frequency vs. time contour. As the frequency is proportional to flow, the integral of this curve corresponds to the overall volume by a linear relationship. The accuracy of vortex whistle volume estimates were assessed using (1) controlled flow rates from a consistent volume calibration syringe, and (2) with 66 subjects between the ages of 18-30 yrs. in comparison to hand-held spirometry and two pneumotach systems. RESULTS: Observations from the calibration syringe experiment confirmed that the vortex whistle and software are able to effectively track the flow rate, with a correlation coefficient between the average flow and the average frequency of r2 = 0.9965. Results from the human VC testing showed that measures obtained using both vortex whistles and hand-held spirometry correlated very strongly (r > 0.94) with computerized pneumotach systems, and the strength of correlations obtained via vortex whistles vs. hand-held spirometry were highly comparable. DISCUSSION & CONCLUSIONS: When coupled with the analysis software described herein, valid and reliable frequency/flow curves and volume estimates may be obtained using a vortex whistle that are highly comparable to the hand-held spirometer. The use of the vortex whistle has the potential to bring measures of basic respiratory function to clinicians and patients alike at a fraction of the cost of currently used spirometric methods.

Phonation With a Variably Occluded Facemask: Effects of Task Duration.

OBJECTIVE: Semioccluded vocal tract (SOVT) exercises are routinely included in many voice therapy programs because they have been shown to improve acoustic, aerodynamic, and patient-reported voice outcomes. One limitation of the traditional SOVT exercise is that the nature of phonation through straws or semioccluded oral postures allows only for single phoneme production. A variably occluded facemask (VOFM) allows for use of articulated connected speech beyond the production of single phonemes, while still providing occlusion and, presumably, the vocal efficiency benefits that arise from it. This study reports on the effect of time duration of phonation with a variably occluded facemask on voice outcomes in patients with voice disorders. DESIGN: Prospective, randomized cohort study. METHODS: Fifteen patients with voice disorders phonated for 5 minutes through a VOFM with diameter openings of 3.2, 6.4, and 9.6 mm. Acoustic and aerodynamic voice measures were collected before and after each occlusion trial. These results were compared to a historical patient group that received the same phonation training for 2 minutes. RESULTS: Positive effect sizes were found for acoustic and aerodynamic improvements for all patients for at least one occlusion diameter. Effect sizes for aerodynamic outcomes were greater in the 5-minute conditions for both the 9.6- and 6.4-mm occlusions than the 2-minute condition. Effect sizes for acoustic outcomes were greater in the 5 minute than 2-minute trial for the 9.6- and 6.4-mm occlusion diameter, but greater in the 2 minute than 5-minute trial for 3.2-mm diameter. DISCUSSION: This study provides evidence that all three occlusion sizes may elicit beneficial changes for different patients; however, 5 minutes of phonation into a facemask with end occlusion of 6.4-mm diameter results in improved acoustic and aerodynamic voice outcomes for many patients with voice disorders. Future studies should further explore phonatory physiologic changes of the VOFM in a larger sample of patients and translate effects into clinical treatment for patients with voice disorders.

Singing In The Mask: Effects Of A Variably Occluded Face Mask On Singing.

OBJECTIVE: A limitation of traditional semi-occluded vocal tract exercises (SOVTE) is the single sustained vowel task that precludes co-articulated singing. This study investigated immediate effects of a variably occluded face mask (VOFM) on vocal effort, acoustic, and aerodynamic measures in sung low and high pitches of healthy singers. DESIGN: Single-group, pre-post intervention study. METHODS: The outlet ports of disposable anesthesia facemasks were fitted with plastic caps with two drilled openings sizes (9.6 mm, 6.4 mm). Twenty-three singers with no voice complaints provided baseline vocal effort, acoustic, and aerodynamic measures in high and low pitches. Participants trained in four conditions: two VOFM sizes (9.6 mm, 6.4 mm) in combination with the 20th and 80th percentile of the singer's pitch range. Participants were trained on three phonatory tasks: repeated consonant/vowel syllables, sung sentence, and sustained vowel. Vocal effort before and after training was compared using a visual-analog scale, while standardized mean differences captured acoustic and aerodynamic changes before and after training. RESULTS: Participants reported decreased vocal effort after VOFM training at all occlusion and pitch combinations. On average, consistent beneficial effect sizes were found in cepstral peak prominence (CPP) and cepstral spectral index of dysphonia (CSID) for all 4 occlusion-pitch combinations, and vocal intensity and mean estimated subglottal pressure increased for all 4 occlusion-pitch training combinations. Changes in mean phonatory airflow and resistance were less consistent. DISCUSSION: There was an immediate effect of decreased vocal effort in singing after VOFM training. Acoustic and aerodynamic effects were variable and modest. Future studies should explore changes in these outcomes after VOFM in singing voice therapy.

Cognitive Mechanisms in Pediatric Voice Therapy - An Initial Examination.

INTRODUCTION: Voice disorders are a common communication disorder in children. Behavioral voice therapy is recommended by both Otolaryngologists and Speech-Language Pathologists as a first-line approach for treatment of benign vocal fold lesions that affect children in large numbers. However, the role of cognitive mechanisms critical to voice therapy have not yet been explored. OBJECTIVE: This proof-of-concept study aims to provide preliminary data on the potential relation between cognitive abilities and behavioral results of voice therapy for children with benign phonotraumatic vocal fold lesions. METHODS: Six children (4;05 -9;02 years) diagnosed with vocal fold nodules completed a battery of cognitive tests from the NEuroPSYchological (NEPSY-II) Assessment and a standard course of "Adventures in Voice" therapy. Recordings pre and post intervention were analyzed acoustically using the Cepstral Spectral Index of Dysphonia (CSID) and perceptually using visual analog scales (VAS) for severity and resonance separately. Raw and age-corrected scaled scores from the NEPSY-II were then examined for their possible relation to voice outcomes. RESULTS: Multiple cognitive functions correlated with voice outcomes. Raw score measures for Design Fluency, Inhibition, Fingertip Tapping, and Narrative Memory correlated favorably with all voice outcome measures. Age correlated with all NEPSY-II raw scores and perceptual voice outcome measures. Scaled scores for Auditory Attention, Design Fluency, Fingertip Tapping (Dominant hand), and Narrative Memory correlated with all voice outcome measures. CONCLUSION: Results suggest that there is merit to further investigation of the relation between cognitive skills and their development and voice treatment outcomes in children with benign phonotraumatic lesions. Future studies with larger samples will build on present findings.

A Two-Stage Cepstral Analysis Procedure for the Classification of Rough Voices.

OBJECTIVES: The objective of this study was to investigate the ability of a two-stage method of cepstral peak identification to effectively discriminate rough vs breathy vs typical voice in sustained vowel productions. It was hypothesized that a dual-stage search for cepstral peak prominences (CPP's) above and below specified quefrency/F0 cutoffs would result in a CPP difference that would be characteristic of the rough, diplophonic voice type. METHODOLOGY: Central one-second portions of sustained vowel /a/ productions were obtained from 90 subjects (rough, breathy, and normophonic voices). All voice samples were analyzed using a a two-stage cepstral analysis process in which a CPPHigh-Low difference value was obtained by identifying cepstral peaks above and below a lower limit for expected F0 (150 Hz for females and 90 Hz for males), called CPPHigh and CPPLow respectively. RESULTS: The CPPHigh-Low difference value was observed to be a highly significant predictor, with negative values for this parameter characteristic of a dominant subharmonic in the voice signal and the perception of diplophonic, rough voice. Correct classification of rough vs nonrough voice samples was 82.2% (sensitivity 0.80 and specificity 0.833). In the consideration of three group classification (breathy vs. normophonic vs. rough), models incorporating two predictors (the CPP obtained from a single search through a 60 to 300 Hz frequency range (CPPDefault) and the CPPHigh-Low difference value) correctly classified 78.88% of the voice samples. CONCLUSIONS: Rough, diplophonic voices were consistently observed to have a subharmonic peak that was greater in amplitude than the cepstral peak obtained within the region of the expected F0, resulting in a negative value for the CPPHigh-Low difference. The two-stage cepstral analysis process described herein is visually intuitive from the graphical display of a cepstrum and is a simple extended calculation derived from cepstral analysis procedures that have been recommended as essential in the acoustic description of vocal quality.

Spectral/Cepstral Analyses of Phonation in Parkinson's Disease before and after Voice Treatment: A Preliminary Study.

PURPOSE: This article examines cepstral/spectral analyses of sustained /α/ vowels produced by speakers with hypokinetic dysarthria secondary to idiopathic Parkinson's disease (PD) before and after Lee Silverman Voice Treatment (LSVT®LOUD) and the relationship of these measures with overall voice intensity. METHODOLOGY: Nine speakers with PD were examined in a pre-/post-treatment design, with multiple daily audio recordings before and after treatment. Sustained vowels were analyzed for cepstral peak prominence (CPP), CPP standard deviation (CPP SD), low/high spectral ratio (L/H SR), and Cepstral/Spectral Index of Dysphonia (CSID) using the KAYPENTAX computer software. RESULTS: CPP and CPP SD increased significantly and CSID decreased significantly from pre- to post-treatment recordings, with strong effect sizes. Increased CPP indicates increased dominance of harmonics in the spectrum following LSVT. After restricting the frequency cutoff to the region just above the first formant and second formant and below the third formant, L/H SR was observed to decrease significantly following treatment. Correlation analyses demonstrated that CPP was more strongly associated with CSID before treatment than after. CONCLUSION: In addition to increased vocal intensity following LSVT, speakers with PD exhibited both improved harmonic structure and voice quality as reflected by cepstral/spectral analysis, indicating that there was improved harmonic structure and reduced dysphonia following treatment.

Effects of a Variably Occluded Face Mask on the Aerodynamic and Acoustic Characteristics of Connected Speech in Patients With and Without Voice Disorders.

OBJECTIVE: This study reports on experiments designed to examine the effects of a variably occluded face mask (VOFM) on (a) estimated subglottal pressure (Psub) in normophonic participants and (b) aerodynamic and acoustic characteristics of voice in dysphonic participants. DESIGN: A prospective design was used for experiment 1, and a prospective, randomized cohort design was used for experiment 2. METHODS: The outlet ports of disposable anesthesia face masks were fitted with plastic caps with variable diameter drilled openings (9.6, 6.4, 3.2, and 1.6 mm) to create a series of mask openings. In experiment 1, Psub was measured in normophonic participants using the face mask during syllable repetitions in unoccluded and variable diameter opening conditions. In experiment 2, aerodynamic and acoustic measures were obtained in a group of dysphonic speakers before and after syllable and speech repetition tasks using the VOFM. RESULTS: In experiment 1, mean PSub was observed to decrease while using the VOFM in all occlusion conditions versus nonocclusion, with a significant reduction in Psub observed between the baseline and the 6.4 mm condition. In experiment 2, standardized mean differences showed that many dysphonic participants produced reduced Psub, increased airflow, and improved acoustic measures after the use of the VOFM in at least one occlusion condition. CONCLUSIONS: Beneficial changes in both aerodynamic and acoustic characteristics of voice may be obtained in dysphonic speakers using a VOFM. By moving the place of occlusion outside of the oral cavity, therapeutic stimuli options may be extended beyond vowel and humming elicitations to syllable and speech contexts and assist with generalization of voice therapy targets to conversational speech.

Recommended Protocols for Instrumental Assessment of Voice: American Speech-Language-Hearing Association Expert Panel to Develop a Protocol for Instrumental Assessment of Vocal Function.

Purpose: The aim of this study was to recommend protocols for instrumental assessment of voice production in the areas of laryngeal endoscopic imaging, acoustic analyses, and aerodynamic procedures, which will (a) improve the evidence for voice assessment measures, (b) enable valid comparisons of assessment results within and across clients and facilities, and (c) facilitate the evaluation of treatment efficacy. Method: Existing evidence was combined with expert consensus in areas with a lack of evidence. In addition, a survey of clinicians and a peer review of an initial version of the protocol via VoiceServe and the American Speech-Language-Hearing Association's Special Interest Group 3 (Voice and Voice Disorders) Community were used to create the recommendations for the final protocols. Results: The protocols include recommendations regarding technical specifications for data acquisition, voice and speech tasks, analysis methods, and reporting of results for instrumental evaluation of voice production in the areas of laryngeal endoscopic imaging, acoustics, and aerodynamics. Conclusion: The recommended protocols for instrumental assessment of voice using laryngeal endoscopic imaging, acoustic, and aerodynamic methods will enable clinicians and researchers to collect a uniform set of valid and reliable measures that can be compared across assessments, clients, and facilities.

An Examination of Pre- and Posttreatment Acoustic Versus Auditory Perceptual Analyses of Voice Across Four Common Voice Disorders.

OBJECTIVE: The objective, instrumental acoustic measure of Cepstral Spectral Index of Dysphonia (CSID) correlates with audio-perceptual measures, is sensitive in detecting voice abnormalities, and tracks change following treatment. The goals of the current study were to (1) test the agreement between CSID versus auditory perceptual measures of pre- versus posttreatment voice change, and (2) investigate whether change in scores is based on voice disorder or phonemic structure of sentence stimuli. METHODS: Forty patients with benign voice disorders produced sentences and a sustained /a/ vowel from the Consensus Auditory Perceptual Evaluation of Voice protocol before and after treatment. CSID was calculated, and overall audio-perceptual voice severity was judged by 7 blinded, trained raters using a 100-mm visual analog scale. Differences between CSID and audio-perceptual measures of voice change across voice disorder and stimuli, and correlation between change in CSID and perceptual rating scores were assessed pre- and postintervention. RESULTS: Across all subjects, there were significant correlations between CSID and perceptual ratings change scores (P < 0.001), and no significant differences in pre- and posttreatment change. Disorder-specific analyses indicated that all tested sentence/vowel contexts are effective measures for pre- versus posttreatment change in atrophy and paralysis cases. Acoustic versus perceptual measures of voice change were significantly correlated in lesion cases for the sentence "How hard did he hit him" and with all sentences combined. There were no significant findings observed for muscle tension dysphonia. CONCLUSION: CSID provides an accurate objective correlate to auditory-perceptual posttreatment change in overall voice severity ratings. Implications for outcomes testing and disorder-specific findings are discussed.

A Comparison of Cepstral Peak Prominence Measures From Two Acoustic Analysis Programs.

PURPOSE: This study aimed to investigate the relationship and reliability of cepstral peak prominence (CPP) measures from two acoustic software applications, Analysis of Dysphonia in Speech and Voice (ADSV) and Praat. METHODOLOGY: Flemish and English recordings of sustained vowels and connected speech samples were analyzed using ADSV and Praat. Correlational analyses and measures of the standard error of the estimate were applied to the vowel and connected speech data obtained from the two programs. RESULTS: Analyses revealed very strong relationships (eg, r > 0.88) between CPP measures derived from ADSV and those derived from Praat, regardless of context (vowel or connected speech) or language spoken. Average residual errors ranged from 0.55 to 1.1 dB for the prediction of Praat CPP data from actual observed ADSV CPP data, and average residual errors ranged from 0.57 to 1.58 dB for the prediction of ADSV CPP data from actual observed Praat CPP data. CONCLUSIONS: Measurements of CPP derived from ADSV and Praat manifested strong parallel-forms reliability. Although CPP data values obtained via these programs will be different owing to algorithmic processing differences, this study found that estimated CPP values derived using regression equations could be transformed between programs with relatively small predictive error, regardless of language. The strong measurement relationships indicate that CPP values from either program have a high degree of shared variance and may be expected to differentiate across a wide range of voice signal periodicity in a relatively similar fashion. This finding supports the use of either program in clinical use and voice science research.

Acoustic and Perceptual Classification of Within-sample Normal, Intermittently Dysphonic, and Consistently Dysphonic Voice Types.

OBJECTIVES: Intermittent dysphonia within an utterance is common, but presents difficulty for both perceptual and objective voice evaluation. This study examined the ability of measures from the within-sample cepstral peak prominence (CPP) distribution to differentiate normal voices from intermittently and consistently dysphonic voices. STUDY DESIGN: Exploratory design. METHODS: Sixty samples of the sentence "We were away a year ago" were classified as normal, intermittently dysphonic, or consistently dysphonic by four judges. Measures of CPP within each sample were obtained, and further analysis with examined CPP distribution variability and patterns of CPP outliers. RESULTS: Whereas the mean CPP was the strongest single discriminator among the three voice types, the normal and intermittent dysphonia groups were not significantly different on CPP distribution skewness and measures of CPP distribution outliers. Both the normal and intermittently dysphonic voices differed significantly from the consistently dysphonic samples on these variables. A combination of measures of the CPP distribution was effective for a linear prediction of percent dysphonia duration for the speech samples (r = 0.825; rho = 0.81). The CPP standard deviation significantly improved the use of the mean CPP in discriminant function analyses and also the classification of the intermittently dysphonic voices. CONCLUSIONS: Auditory-perceptual judgment of dysphonic segments and the typically robust acoustic measurement of mean CPP are both ineffective for classifying intermittently dysphonic voices. However, dysphonia duration may be effectively predicted via measures of the CPP distribution, and acoustic classification of dysphonic voice types via cepstral methods may be improved with an analysis of the CPP distribution across an utterance.