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.

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.

Adductor Laryngeal Dystonia Versus Muscle Tension Dysphonia: Examining the Utility of Automated Acoustic Analysis to Detect Task Dependency as a Distinguishing Feature.

OBJECTIVE: Differentiating adductor laryngeal dystonia (ADLD) and primary muscle tension dysphonia (pMTD) can be challenging. Unlike pMTD, ADLD is described as "task-dependent" with voiced phonemes purportedly provoking greater sign expression than voiceless phonemes. We evaluated the ability of two automated acoustic measures, the Cepstral Spectral Index of Dysphonia (CSID) and creak, to detect task dependency and to discriminate ADLD and pMTD. METHOD: CSID, % creak, and listener ratings of dysphonia severity were obtained from audio recordings of patients with ADLD (n = 29) or pMTD (n = 33) reading two sentences loaded with either voiced or voiceless phonemes. RESULTS: Group × Sentence Type interaction effects confirmed that both "normalized" CSID and % creak detected task-dependent sign expression in ADLD (i.e., worse symptoms on the voiced- vs. voiceless-loaded sentence). However, a stepwise binary logistic regression analysis with group (ADLD vs. pMTD) as the dependent variable and % creak and normalized CSID variables (voiced, voiceless, and voiced vs. voiceless difference) as covariates revealed that the normalized CSID voiceless-laden sentence z score was the only significant predictor of group membership. Estimates of diagnostic precision from the normalized CSID voiceless sentence z scores were superior to % creak or listener ratings. Finally, the CSID possessed the strongest correlations with listener severity ratings regardless of group or sentence type. CONCLUSIONS: Although both normalized CSID and % creak detected task-dependent performance as a distinguishing feature of ADLD, a CSID profile wherein (a) the voiceless sentence z score was less severe than the voiced sentence and (b) the normalized voiceless sentence z score was within approximately 2 SDs (or less) of typical expectations provided the best estimates of diagnostic precision. Automated acoustic measures such as the CSID and creak provide useful information to objectively discriminate ADLD and pMTD.

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.

Evidence-Based Recommendations for Tablet Recordings From the Bridge2AI-Voice Acoustic Experiments.

BACKGROUND: As part of a larger goal to create best practices for voice data collection to fuel voice artificial intelligence (AI) research, the objective of this study was to investigate the ability of readily available iOS and Android tablets with and without low-cost headset microphones to produce recordings and subsequent acoustic measures of voice comparable to "research quality" instrumentation. METHODS: Recordings of 24 sustained vowel samples representing a wide range of typical and disordered voices were played via a head-and-torso model and recorded using a research quality standard microphone/preamplifier/audio interface. Acoustic measurements from the standard were compared with two popular tablets using their built-in microphones and with low-cost headset microphones at different distances from the mouth. RESULTS: Voice measurements obtained via tablets + headset microphones close to the mouth (2.5 and 5 cm) strongly correlated (r's > 0.90) with the research standard and resulted in no significant differences for measures of vocal frequency and perturbation. In contrast, voice measurements obtained using the tablets' built-in microphones at typical reading distances (30 and 45 cm) tended to show substantial variability in measurement, greater mean differences in voice measurements, and relatively poorer correlations vs the standard. CONCLUSION: Findings from this study support preliminary recommendations from the Bridge2AI-Voice Consortium recommending the use of smartphones paired with low-cost headset microphones as adequate methods of recording for large-scale voice data collection from a variety of clinical and nonclinical settings. Compared with recording using a tablet direct, a headset microphone controls for recording distance and reduces the effects of background noise, resulting in decreased variability in recording quality. DATA AVAILABILITY: Data supporting the results reported in this article may be obtained upon request from the contact author.

Spectral-cepstral estimation of dysphonia severity: external validation.

OBJECTIVES: The current study applied an acoustic algorithm incorporating measures from cepstral and spectral analyses, the Cepstral Spectral Index of Dysphonia (CSID), in an attempt to externally validate the CSID as an acoustic estimate of dysphonia severity. METHODS: Correlation (Pearson's r) between the CSID and trained listener-perceived severities as rated on the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) was calculated from sentence and sustained vowel samples from 56 patients before or after they underwent thyroid surgery. RESULTS: A strong correlation was identified between the mean CSID values calculated across CAPE-V sentences and vowels and the median rating of perceived overall severity (r = 0.82; p < 0.001). The CSID values did not differ significantly from their corresponding auditory-perceptual ratings of dysphonia severity for these samples (CSID: mean, 15.54, SD, 16.63; CAPE-V Severity: mean, 17.33, SD, 13.61; p = 0.16). CONCLUSIONS: Independent testing of an acoustic algorithm incorporating measures from cepstral and spectral analyses (the CSID) confirmed a strong correlation of the CSID to perceptual ratings of overall voice quality. This study provides external validation of the CSID as a robust correlate of dysphonia severity as rated by trained listeners.

Nasometer 6200 Versus Nasometer II 6400: Effect on Measures of Nasalance.

Objective : This study compared measures of nasalance obtained using the Nasometer 6200 versus the Nasometer II 6400 in typically speaking young adult males and females for the nonnasal Zoo Passage, the phonetically balanced Rainbow Passage, and the Nasal Sentences. Design : Participants read passages at a comfortable pitch and loudness twice while wearing Nasometer 6200 or Nasometer II 6400 headgear. The order of Nasometer system was counterbalanced across participants, and the order of the reading passage was randomized. Participants : Participants consisted of 25 males (mean age = 21.22 years) and 25 females (mean age = 23.83 years). Main Outcome Measures : The main outcomes measures were nasalance scores (%) obtained for each system × passage per participant. Results : Results showed that the Nasometer 6200 and the Nasometer II 6400 differed significantly on mean nasalance for the Zoo Passage (mean difference = 7.15%) and the Rainbow Passage (mean difference = 3.05%) but not for the Nasal Sentences (mean difference = 0.77%). Intersystem correlations and measures of predictive accuracy indicated that the ability to predict Nasometer 6200 nasalance scores from Nasometer II 6400 scores was relatively weak. Conclusions : In addition to such factors as age, gender, and regional dialect, normative nasalance expectations and normal versus disordered nasalance cutoff scores must be considered with full knowledge of the specific system that was used to acquire the nasalance data. Intrasubject changes in nasalance can only be validly assessed when test versus retest measurements have been acquired using the same nasalance system.

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.

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.

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.

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.

Spectral- and cepstral-based acoustic features of dysphonic, strained voice quality.

OBJECTIVES: We sought to determine whether spectral- and cepstral-based acoustic measures were effective in distinguishing dysphonic-strained voice quality from normal voice quality and whether these measures were related to auditory-perceptual ratings of strain severity. METHODS: Voice samples from 23 speakers with dysphonia characterized predominantly by strained voice quality and 23 speakers with normal voice were acoustically analyzed. Measures related to the prominence of the cepstral peak and the ratio of low- to high-frequency spectral energies, as well as the variation of each, were computed from continuous speech and a sustained vowel. Correlations to perceptually rated strain severity were determined. RESULTS: Measures related to the cepstrum were the strongest discriminators between dysphonic-strained voice and normal voice. Variation in the ratio of low- to high-frequency spectral energies also significantly differentiated the two speaker groups. All measures were significantly correlated with perceptually rated strain severity, including an acoustic severity index that incorporated both cepstral- and spectral-based measures. CONCLUSIONS: Cepstral- and spectral-based measures that have been previously studied in dysphonia characterized by breathiness and roughness are effective in distinguishing strained dysphonia from normal voice quality. The utility of these acoustic measures is supported by their moderate-to-high relationship with perceptually rated strain severity.

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.

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.

Investigation of fatigue, delayed-onset muscle soreness, and spectral-based cepstral measurements in healthy speakers after neuromuscular electrical stimulation.

OBJECTIVES: We observed whether 30 minutes of neuromuscular electrical stimulation applied to the necks of healthy speakers would result in significant acoustic changes and perceptions of fatigue and/or delayed-onset muscle soreness (DOMS). METHODS: Twelve participants were assigned to experimental (n=6; 3 male and 3 female) and control groups (n=6; 3 male and 3 female). Neuromuscular electrical stimulation was applied to the anterior neck in the experimental group only. All participants produced 3 trials of the vowel /a/ and the Rainbow Passage before and after completing a 30-minute phonation protocol. Recorded samples were analyzed for measures of the cepstral peak prominence, the ratio of low- to high-frequency spectral energy, and their respective standard deviations. Perceptions of fatigue and DOMS were rated on visual analog scales before, 5 minutes after, and 24 hours after completion of the phonation protocol. RESULTS: Statistically significant acoustic findings reflecting reduced relative sound pressure level, increased high-frequency noise, and phonatory instability were observed in the experimental group. In addition, reports of fatigue and DOMS were also reported by some participants. CONCLUSIONS: A 30-minute dosage may be too high for some people experiencing neuromuscular electrical stimulation for the first time.

The effect of smoking on the dysphonia severity index in females.

OBJECTIVE: This study investigated the capability of the Dysphonia Severity Index (DSI) and its component measures to reveal differences in vocal capability between groups of young adult female smokers and nonsmokers. PATIENTS AND METHODS: The subjects were 30 female nonsmokers and 30 female smokers between the ages of 18 and 24 years. Data on the DSI components (maximum phonation time, MPT; highest phonational frequency, F(0 high); lowest intensity, I(low), and jitter) were collected, followed by calculation of the DSI. RESULTS: Significant differences between groups were observed on the DSI, with reduced DSI scores in smokers primarily due to reductions in F(0 high) and increases in I(low). A strong partial correlation between MPT and the DSI in smokers may be indicative of reductions in respiratory support and/or phonatory control. CONCLUSIONS: Significant group differences in the DSI and component measures may be indicative of early changes in vocal function secondary to smoking. Reductions in frequency and dynamic range are consistent with the possibility of increased vocal fold mass in smokers. The results indicate that significant differences in the DSI between groups may be observed in subjects with perceptually normal vocal quality and with normal levels of vocal perturbation.

Voice onset time in Indian English-accented speech.

The purpose of this study was to determine possible differences in voice onset time (VOT) between speakers of standard American English (AE) and Indian English (IE) in a continuous speech context. The participants were 20 AE speakers, who were native to the Northeastern Pennsylvania region, and 20 IE speakers from the Indian subcontinent who had been residing in Northeastern Pennsylvania. Each subject read a phonetically balanced passage in a comfortable and natural speaking voice, and the recordings were analysed using a combination of waveform and spectrographic analyses. Results indicate that a reduced +VOT appears to characterise IE accent in comparison to AE. In addition, a difference in VOT between genders was observed in AE speakers but not in IE speakers.

Tracking voice change after thyroidectomy: application of spectral/cepstral analyses.

This study evaluates the utility of perioperative spectral and cepstral acoustic analyses to monitor voice change after thyroidectomy. Perceptual and acoustic analyses were conducted on speech samples (sustained vowel /α/ and CAPE-V sentences) provided by 70 participants (36 women and 34 men) at four study time points: prior to thyroid surgery and 2 weeks, 3 months and 6 months after thyroidectomy. Repeated measures analyses of variance focused on the relative amplitude of the dominant harmonic in the voice signal (cepstral peak prominence, CPP), the ratio of low-to-high spectral energy, and their respective standard deviations (SD). Data were also examined for relationships between acoustic measures and perceptual ratings of overall severity of voice quality. Results showed that perceived overall severity and the acoustic measures of the CPP and its SD (CPPsd) computed from sentence productions were significantly reduced at 2-week post-thyroidectomy for 20 patients (29% of the sample) who had self-reported post-operative voice change. For this same group of patients, the CPP and CPPsd computed from sentence productions improved significantly from 2-weeks post-thyroidectomy to 6-months post-surgery. CPP and CPPsd also correlated well with perceived overall severity (r = -0.68 and -0.79, respectively). Measures of CPP from sustained vowel productions were not as effective as those from sentence productions in reflecting voice deterioration in the post-thyroidectomy patients at the 2-week post-surgery time period, were weaker correlates with perceived overall severity, and were not as effective in discriminating negative voice outcome (NegVO) from normal voice outcome (NormVO) patients as compared to the results from the sentence-level stimuli. Results indicate that spectral/cepstral analysis methods can be used with continuous speech samples to provide important objective data to document the effects of dysphonia in a post-thyroidectomy patient sample. When used in conjunction with patient's self-report and other general measures of vocal dysfunction, the acoustic measures employed in this study contribute to a complete profile of the patient's vocal condition.

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.