The validity of the Acoustic Breathiness Index in the evaluation of breathy voice quality: A Meta-Analysis.

BACKGROUND: The evaluation of voice quality with acoustic measurements is useful to objectify the diagnostic process. Particularly, breathiness was highly evaluated and the Acoustic Breathiness Index (ABI) might have promising features. OBJECTIVE OF REVIEW: The goal of the present meta-analysis is to quantify, from existing cross-validation studies, the evidence for the diagnostic accuracy of ABI, including its sensitivity and specificity. TYPE OF REVIEW: Meta-analysis. SEARCH STRATEGY: We searched in MEDLINE, Google Scholar and Science Citation Index, and as manual search for the term Acoustic Breathiness Index from inception to February 2020. Studies were included that used equal proportion of continuous speech and sustained vowel segments, a recording hardware with a sufficient standard for voice signal analyses, the software Praat for signal processing and the customised Praat script, and two groups of subjects (vocally healthy and voice-disordered). Furthermore, the diagnostic accuracy of ABI was measured. EVALUATION METHOD: The primary outcome variable was ABI. The score ranged from 0 to 10 with varying thresholds according to different languages to determine the absence or presence of breathiness. A meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses of diagnostic test accuracy study guidelines. Data were extracted, and the risk of bias was assessed using the QUADAS-2 tool. The pooled sensitivity and specificity of ABI were determined using a summary receiver operating characteristic (SROC) approach to calculate also a weighted threshold value of ABI with its sensitivity and specificity. RESULTS: A total of 34 unique citations were screened, and 10 full-text articles were reviewed, including six studies. In total, 3603 voice samples were considered for further analysis separating into 467 vocally healthy and 3136 voice-disordered voice samples. The pooled sensitivity was 0.84 (95% CI, 0.83-0.85), and the pooled specificity was 0.92 (95% CI, 0.89-0.94). The area under the curve of the SROC curve of this analysis showed an excellent value of 0.94. The weighted ABI threshold was determined at 3.40 (sensitivity: 0.86, 95% CI, 0.84-0.87.; specificity: 0.90, 95% CI 0.88-0.92). CONCLUSIONS: The results confirm the ABI as robust and valid objective measure for evaluating breathiness.

Measurement of the Maximum Frequency of Electroglottographic Fluctuations in the Expiration Phase of Volitional Cough as a Functional Test for Cough Efficiency.

The hypotheses of the present study were that the maximum frequency of fluctuation of electroglottographic (EGG) signals in the expiration phase of volitional cough (VC) reflects the cough efficiency and that this EGG parameter is affected by impaired laryngeal closure, expiratory effort strength, and gender. For 20 normal healthy adults and 20 patients diagnosed with unilateral vocal fold paralysis (UVFP), each participant was fitted with EGG electrodes on the neck, had a transnasal laryngo-fiberscope inserted, and was asked to perform weak/strong VC tasks while EGG signals and a high-speed digital image of the larynx were recorded. The maximum frequency was calculated in the EGG fluctuation region coinciding with vigorous vocal fold vibration in the laryngeal HSDIs. In addition, each participant underwent spirometry for measurement of three aerodynamic parameters, including peak expiratory air flow (PEAF), during weak/strong VC tasks. Significant differences were found for both maximum EGG frequency and PEAF between the healthy and UVFP groups and between the weak and strong VC tasks. Among the three cough aerodynamic parameters, PEAF showed the highest positive correlation with the maximum EGG frequency. The correlation coefficients between the maximum EGG frequency and PEAF recorded simultaneously were 0.574 for the whole group, and 0.782/0.717/0.823/0.688 for the male/female/male-healthy/male-UVFP subgroups, respectively. Consequently, the maximum EGG frequency measured in the expiration phase of VC was shown to reflect the velocity of expiratory airflow to some extent and was suggested to be affected by vocal fold physical properties, glottal closure condition, and the expiratory function.

A Comparison of Visual Recognition of the Laryngopharyngeal Structures Between High and Standard Frame Rate Videos of the Fiberoptic Endoscopic Evaluation of Swallowing.

The purpose of this study was to assess whether or not high frame rate (HFR) videos recorded using high-speed digital imaging (HSDI) improve the visual recognition of the motions of the laryngopharyngeal structures during pharyngeal swallow in fiberoptic endoscopic evaluation of swallowing (FEES). Five healthy subjects were asked to swallow 0.5 ml water under fiberoptic nasolaryngoscopy. The endoscope was connected to a high-speed camera, which recorded the laryngopharyngeal view throughout the swallowing process at 4000 frames/s (fps). Each HFR video was then copied and downsampled into a standard frame rate (SFR) video version (30 fps). Fifteen otorhinolaryngologists observed all of the HFR/SFR videos in random order and rated the four-point ordinal scale reflecting the degree of visual recognition of the rapid laryngopharyngeal structure motions just before the 'white-out' phenomenon. Significantly higher scores, reflecting better visibility, were seen for the HFR videos compared with the SFR videos for the following laryngopharyngeal structures: the posterior pharyngeal wall (p = 0.001), left pharyngeal wall (p = 0.015), right lateral pharyngeal wall (p = 0.035), tongue base (p = 0.005), and epiglottis tilting (p = 0.005). However, when visualized with HFR and SFR, 'certainly clear observation' of the laryngeal structures was achieved in <50% of cases, because all the motions were not necessarily captured in each video. These results demonstrate the use of HSDI in FEES makes the motion perception of the laryngopharyngeal structures during pharyngeal swallow easier in comparison to SFR videos with equivalent image quality due to the ability of HSDI to depict the laryngopharyngeal motions in a continuous manner.

[A clinical investigation of pediatric patients with sleep-disordered breathing who suffered perioperative respiratory complications of adenotonsillectomy].

The aim of this study was to investigate the clinical background and identify the risk factors for perioperative respiratory complication in pediatric patients with sleep-disordered breathing (SDB) who underwent adenotonsillectomy (AT). Of the 186 pediatric subjects (male: 131, female: 55) undergoing AT as the first surgical treatment for SDB, 14 patients (male: 9, female: 5) fulfilled the following criteria: 1) disturbed ventilation, 2) cyanosis with an oxygen saturation of less than 90% on pulse oximetry during the perioperative period and 3) the subsequent need for medical intervention, including immediate intubation, continuous positive airway pressure (CPAP) or airway insertion. Among these 14 patients, nine were less than 3 years of age. In addition, 5 and 3 patients had hypotonia due to cerebral paralysis and metabolic disturbances, respectively. Seven had a short stature with an SD of worse than - 1.5. A statistical analysis showed that cases with either an age of less than 3 years, hypotonia or a short stature had a high risk for suffering from respiratory complications, and suggested that low body weight and a high value for preoperative apnea-hypopnea index were additional risk factors. However, a chart review exhibited that, of the 14 cases with respiratory complications, the 8 cases whose age was under 3 years had either of hypotonia or a short stature. In thirteen of the 14 cases, respiratory complications were associated with the process of general anesthesia, and ten patients exhibited pharyngeal collapse. After surgery, 7 and 3 patients required intensive care in the ICU and the pediatric recovery unit, respectively. Based on these results, it is suggested that pediatric SDB cases under 3 years of age and either with hypotonia or a short stature have a high risk for respiratory complications associated with AT, and therefore AT for such patients should only be performed in medical facilities with an ICU or an equivalent department.

Botulinum toxin injection for abductor spasmodic dysphonia under cervical ultrasonography guidance.

Ultrasound (US) imaging effectively provides real-time anatomical information for clinical examinations. In otolaryngology, US imaging can visualize laryngeal muscles as well as cervical muscles. Here we present the case where US imaging was used while injecting botulinum toxin (BT) for the treatment of abductor spasmodic dysphonia, which provided definite results. We could visualize not only the injection pathway but also the infiltration of the BT solution into the posterior cricoarytenoid muscles. Therefore, our laryngeal US imaging is useful for both improving the success rate and avoiding injection complications of BT.

Changes in serum lactate dehydrogenase as a prognostic factor in patients with head and neck squamous cell carcinoma treated with immune checkpoint inhibitors.

BACKGROUND: Lactate dehydrogenase (LDH) is involved in the Warburg effect. Elevated serum LDH is a prognostic marker for metastatic solid cancer. AIM: To investigate the prognostic impact of serum LDH in patients with head and neck squamous cell carcinoma treated with immune checkpoint inhibitors (ICIs). MATERIALS AND METHODS: This retrospective study included 129 patients treated with ICIs between 2017 and 2023. The effects of pretreatment LDH, LDH at 3 months, and change in LDH during the first 3 months (ΔLDH) on overall survival (OS) and progression-free survival (PFS) were analyzed using the Kaplan-Meier method and Cox regression model. RESULTS: The 1-year PFS and OS rates for high and low groups were 6.0% and 30.1% for pretreatment LDH (p = 0.044), 25.7% and 38.3% for on-treatment LDH (p = 0.079), and 14.3% and 38.7% for ΔLDH (p = 0.008), as well as 42.1% and 60.9% for pretreatment LDH (p = 0.109), 56.0% and 80.5% (p < 0.001) for on-treatment LDH, and 31.0% and 81.0% for ΔLDH (p < 0.001), respectively. ΔLDH was an independent prognostic factor for both PFS and OS. CONCLUSIONS AND SIGNIFICANCE: ΔLDH can be used to predict ICI treatment outcomes and as a marker in deciding to continue ICI therapy.

The Minimal Important Difference of Acoustic Voice Quality Index in the Treatment of Voice Disorders.

OBJECTIVES: The acoustic voice quality index (AVQI) is a reliable tool that objectively assesses dysphonia levels using six acoustic parameters. Despite its high criterion-related concurrent validity, diagnostic accuracy, and minimal detectable change derived from test-retest reliability, the minimal important difference (MID) of the AVQI has not been tested before. This study aimed to estimate the MIDs of AVQI for improvement audibly perceived by clinicians and self-reported improvement by patients. METHODS: A retrospective study was conducted on 110 patients who received treatment for voice disorders. Patients completed AVQI and Voice Handicap Index-10 (VHI-10) questionnaires before and after the therapy. The MIDs of the AVQI were estimated using the anchor of either auditory-perceptual judgment of total dysphonia levels by clinicians or the VHI-10 questionnaire by patients. A distribution-based approach was also used to complement the results. RESULTS: First, using the auditory-perceptual anchor, a decrease of 0.95 in the AVQI was estimated as the MID for clinicians' perception, as a result of the receiver operating curve. Then, using the patient-reported anchor, an improvement of 1.36 in the AVQI was estimated as the MID for patients' voice-related disability. The distribution-based approach also ensured the anchor-based results of both the MIDs. CONCLUSIONS: The AVQI is a reliable and valid tool for evaluating voice quality, and a 0.95 decrease in the AVQI represents a meaningful improvement for clinicians' perception, whereas a 1.36 decrease in the AVQI influences patients' self-reported disability. This study contributes to understanding the minimal change necessary for clinicians to make informed decisions and ensure patient satisfaction. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:2805-2811, 2024.

Temporal recovery and prognostic factors for dysphagia following cardiovascular surgery: Retrospective analysis and development of predictive score.

OBJECTIVE: Dysphagia is a common complication associated with cardiovascular surgery (CVS). This study sought to better understand recovery timelines, identify risk factors, and create a prognostic model for oral intake restoration. METHODS: This retrospective study included 134 patients who had CVS between April 2022 and March 2024. We assessed swallowing ability through fiberoptic endoscopic evaluation of swallowing (FEES). We randomly divided the patients' data into a training dataset and a test dataset in a ratio of 70/30 and Kaplan-Meier analyses and Cox regression were used to assess predictors of total oral intake. We also created a scoring system using the estimated regression coefficients. RESULTS: Most patients with CVS achieved total oral intake in 7-11 days after extubation. Over 168 h of intubation, the presence of penetration or aspiration, a poor FEES score (score > 6), and perioperative complications were significant risk factors for delayed total oral intake. The predicting score was calculated by adding the scores for each individual factor, including FEES score, penetration/aspiration, and preoperative complications. Scores ranged 0-8, categorizing patients into 0-2, 3-5, and 6-8 groups, clearly demonstrating that the higher the predicting score, the longer the time to total oral intake in both the training and the test dataset. CONCLUSIONS: All risk factors for unsuccessful or delayed total oral intake were intubation for more than a week, poor swallowing ability, and the presence of perioperative complications. The scoring system accurately predicts the restoration of oral intake following CVS.

Sex Differences in Predicting Difficult Laryngeal Exposure: Validation and Modification of Predictive Models.

OBJECTIVES/HYPOTHESIS: To determine the presence of sex differences in difficult laryngeal exposure and the Laryngoscore, validate the Laryngoscore, mini-Laryngoscore, and Clarysse's model for predicting difficult laryngeal exposure, and modify the Laryngoscore for improved prediction accuracy. STUDY DESIGN: Retrospective study. METHODS: This study included 153 patients who underwent laryngeal microsurgery at a tertiary laryngology center and university hospital. Patients were evaluated using the 11 items of the Laryngoscore, mini-Laryngoscore, and Clarysse's model to predict difficult laryngeal exposure. Difficult laryngeal exposure was defined as the inability to view the anterior commissure through a rigid laryngoscope under counterpressure to the anterior neck. Descriptive statistics and receiver-operating characteristic curve analysis were used to assess the diagnostic performance of the predictive models and variables, including sex. RESULTS: The prevalence of difficult laryngeal exposure was significantly higher in men than in women, despite higher Laryngoscore values in females. The Laryngoscore, mini-Laryngoscore, and Clarysse's model demonstrated good diagnostic performance with C-indexes of 0.751, 0.727, and 0.783, respectively. Based on these findings, we proposed a modified Laryngoscore, including treatment history, interincisors gap, upper jaw dental status, thyro-mental distance, degree of neck flexion-extension, and sex, achieving a C-index of 0.835. CONCLUSIONS: Inclusion of sex in the Laryngoscore and related predictive models enhances the accuracy of predicting difficult laryngeal exposure. These findings support the inclusion of sex as a factor in future modifications of these models to improve their predictive performance.

Immediate effectiveness of humming on the supraglottic compression in subjects with muscle tension dysphonia.

AIMS: To verify whether humming corrects supraglottic compression in muscle tension dysphonia (MTD) patients. METHODS: We enrolled 23 MTD participants (13 male, 10 female) showing supraglottic compression. Each individual was instructed to perform 3 types of phonation under transnasal laryngofiberscopy: natural phonation, humming phonation without pitch change and subsequent um-hum phonation, i.e. humming with pitch glide up as if agreeing with someone. The degree of supraglottic compression was estimated with 2 parameters. The false vocal fold and anterior-posterior indices (the FVF and AP indices) were calculated by normalizing the lateral width and AP length of the visible vocal cords at phonation normalized to the mean vocal cord length at inspiration, respectively. These indices were compared among the tasks. RESULTS: All the MTD participants but 5 females accomplished decreases in the vocal roughness scores upon the phonatory tasks. The whole MTD group showed significant increases in the FVF and AP indices even after humming without pitch change with a dominance of the AP index. The humming-responsive MTD subgroup showed greater increases in both indices than the humming-resistant subgroup. CONCLUSION: These data demonstrate that humming corrects both the lateral and AP components of supraglottic compression in most MTD patients.

A Case of Pharyngeal Stenosis Caused by Behçet's Disease Treated With Transoral Videolaryngoscopic Surgery.

Behçet's disease is a refractory inflammatory disease characterized by recurrent oral aphthous ulcers. Ulcers are commonly seen in the oral cavity and the pharyngeal region. In patients with recurrent pharyngeal ulcers, pharyngeal stenosis may occur and leads to dysphagia. Herein, we report a case of pharyngeal stenosis caused by recurrent ulcers due to incomplete Behçet's disease. Prednisolone, colchicine, and infliximab were administered and resolved the pharyngeal ulcers, however, dysphagia persisted. To improve the swallowing function, a pharyngeal dilation surgery and transoral videolaryngoscopic surgery were performed, which resulted in an enlarged pharyngeal cavity. Oral intake of water was initiated the day after surgery, and after six days, the patient was able to take a normal diet. The pharyngeal stenosis had not recurred for one year after the surgery, and a normal diet continued without any dietary restrictions. Therefore, in a case of a severe oropharyngeal lesion, periodic follow-up and surgical interventions by an otolaryngologist are necessary.

Skin Acceleration Levels Estimated by a Neck-surface Accelerometer during Phonation Are Affected by The Mechanical Properties of The Anterior Cervical Skin.

OBJECTIVES: The aim of the present study was to assess whether skin acceleration levels (SAL) estimated by a neck-surface accelerometer (ACC) are affected by the anterior neck skin condition. METHODS: Each of six healthy non-dysphonic participants wore a headset microphone (MIC), had an ACC sensor fitted on the skin over the cervical trachea, and were subsequently asked to gradually increase the vocal loudness during sustained phonation of the vowel /e:/ (crescendo task), while the sound pressure levels on a sound level meter (SPLSLM) and MIC/ACC signals were simultaneously recorded. Root mean squared values were calculated from the MIC and ACC signals as the sound pressure level (SPLMIC) and SAL, respectively, and the relationships between SPLSLM and SAL were compared between neck anteflexion and retroflexion or between outward and inward skin retraction on both sides of the sensor. RESULTS: In the total samples for the successful crescendo performance in a natural head position, the SPLMIC and SPLSLM showed a strong linear correlation (r=0.980), whereas the correlation between the SAL and SPLSLM showed a distorted regression line (r=0.765) with individual differences. In all participants, the anteflexion and inward skin retraction decreased the SAL value at the same SPLSLM value, whereas the retroflexion increased the SAL value at the same SPLSLM value. CONCLUSION: These results demonstrate that the signal intensity of a neck-surface ACC is affected by the condition of the anterior cervical skin, perhaps leading to inter-individual variability in SAL measurements.

The Feasibility of Gastroesophageal Manometry for Continuously Evaluating the Degree of Expiratory Effort During Successful Crescendo Phonation.

OBJECTIVES: This study aimed to assess the feasibility of gastroesophageal manometry for continuously evaluating the degree of expiratory effort by measuring the pressures in the digestive tract during crescendo phonation. METHODS: Each of 18 healthy nondysphonic speakers had a probe with a four-channel gastroesophageal manometer inserted through the nasal cavity to place four pressure sensors in the hypopharynx, cervical-/thoracic esophagus, and stomach, and was asked to gradually increase the vocal loudness during sustained phonation of the vowel /e:/ (vowel-crescendo task), while the sound pressure level and the pressures were simultaneously recorded. RESULTS: 50% of the successful vowel-crescendo task samples with a gradual and adequate sound pressure level increase showed a concomitant gradual increase in both the intra-thoracic-esophageal/intra-gastric pressure values from approximately -5 mmHg /6 mmHg to -10 mmHg/20 mmHg, respectively. The maximum pressure value was the highest in the intra-gastric pressure followed by the intra-thoracic-esophageal and intra-cervical-esophageal pressures in order. However, most of the samples showed less than one of atypical pressure changes, such as fluctuations in the intra-thoracic-esophageal and intra-gastric pressure changes and dispersion in the intra-cervical-esophageal and intra-hypopharyngeal pressure values (perhaps due to the peristaltic motions, and the contact of the sensors to the membranous wall). CONCLUSION: These results show that, during successful crescendo phonation, gastroesophageal manometry reveals a gradual increase in the intra-thoracic and intra-abdominal pressures with increasing the vocal intensity, even though showing some systematic errors, suggesting the usefulness of gastroesophageal manometry for continuously evaluating the degree of expiratory effort without influence by the laryngeal condition.

Validation of Subharmonics Quantification Using Two-Stage Cepstral Analysis.

OBJECTIVES: Hoarseness is primarily perceived as breathiness or roughness. Despite the various tools that quantitatively assess hoarseness, roughness has been difficult to quantify because of its complex acoustic structure, such as subharmonics. The parameter obtained from the two-stage cepstral analysis is promising for evaluating roughness. Thus, this study aimed to improve the accuracy of the parameter using a customized pitch setting and investigate the relationship between roughness and subharmonics. STUDY DESIGN: The design is a retrospective study. METHODS: Two-stage cepstral analysis was used to analyze the voice recordings of 455 participants, speech impaired and normal controls, using the Analysis of Dysphonia in Speech and Voice and Praat software. For validation, the ground truth of subharmonics was visually quantified using a narrowband spectrogram. The reliability and validity of the two-stage cepstral analysis and subharmonics measures on spectrograms were evaluated. RESULTS: The two-stage cepstral analysis showed a very strong correlation (r = 0.963) between the two software programs. Intra- and inter-rater reliability of the subharmonics measures on spectrograms were also good. Two-stage cepstral analysis showed that even with customized pitch settings, the diagnostic systems and correlations for perceptual roughness and subharmonics were weak to moderate. The subharmonics measures on spectrograms showed a strong correlation with roughness and moderate diagnostic accuracy of subharmonics. CONCLUSIONS: The two-stage cepstral analysis showed some improvement in diagnostic accuracy and correlation with customized pitch settings, but it did not sufficiently detect subharmonics or roughness. The analysis using subharmonics measures on spectrograms proved the high correlation between subharmonics and roughness, indicating that developing acoustic analysis parameters that sufficiently detect subharmonics is necessary.

The Significant Influence of Hoarseness Levels in Connected Speech on the Voice-Related Disability Evaluated Using Voice Handicap Index-10.

OBJECTIVES: This retrospective study examines the influence of voice quality in connected speech (CS) and sustained vowels (SV) on the voice-related disability in patients' daily living documented by Voice Handicap Index-10 (VHI-10). METHODS: A total of 500 voice recordings of CS and SV samples from 338 patients with voice disturbances were included, along with the patients' age, diagnoses, maximum phonation time, and VHI-10. Dataset-1 comprised of 338 untreated patients, whereas Dataset-2 included 162 patients before and after phonosurgeries. As a preliminary study, the concurrent and diagnostic validities based on auditory-perceptual judgments were examined for cepstral peak prominence (CPP) and CPP smoothed (CPPS) for CS and SV tasks. Next, simple correlations and multivariate regression analyses (MRA) were performed to identify which of the acoustic measures for the CS or SV tasks significantly influenced the total score or improvement of VHI-10. RESULTS: The preliminary study confirmed high correlations with hoarseness levels as well as the excellent diagnostic accuracy of CPP and CPPS for both CS and SV tasks. In Dataset-1, the simple correlations and MRA results showed that cepstral measures in both tasks demonstrated moderate correlations with, and significant contribution to the total score of VHI-10, respectively. However, in Dataset-2, the changes of cepstral measures, as well as the median pitch after phonosurgeries in the CS tasks only, showed significant contributions to the improvement of VHI-10. CONCLUSION: The study demonstrated that the hoarseness levels in both the CS and SV tasks equivalently influenced the VHI-10 scores, and that the post-surgical change of voice quality only in the CS tasks influenced the improvement of voice-related disability in daily living.

The Feasibility of a Neck-Surface Accelerometer for Estimating the Amount of Acoustic Output During Phonation Regardless of the Difference in the Mouth Configuration.

OBJECTIVES: This study aimed to assess the feasibility of a neck-surface accelerometer (ACC) for estimating the amount of acoustic output produced during phonation regardless of individual differences or the mouth configuration. METHODS: The sound pressure levels (SPL) and signals of a neck-surface ACC were simultaneously recorded, while each of healthy nondysphonic speakers was asked to perform the following phonatory tasks: (1) repetitive phonation of the vowel /e:/ at various loudness levels; (2) gradually increasing vocal loudness (crescendo) during sustained phonation of the vowel /e:/; (3) repetitive smooth transition between phonation of the vowel /a:/ and /u:/ with the same vocal effort or between phonation of the vowel /e:/ and production of a hum /m:/. The skin acceleration levels (SAL) were calculated from the ACC signals. RESULTS: Although the correlations between the SPL and SAL values were nearly linear in both repetitive-vowel-phonation and vowel-crescendo tasks, the crescendo task showed a higher correlation within individuals than the repetitive task, but with substantial individual differences. The correlation between the increments in the SPL and SAL was higher than that between the SPL and SAL. In the smooth-transition tasks, the SAL-but not the SPL-showed no significant differences between the vowels or hum. CONCLUSION: These results show that the signal intensity of a neck-surface ACC reflects the amount of acoustic output during phonation irrespective of the mouth configuration, but shows nonnegligible individual differences. The use of the increment in the SAL is suggested to be suitable for comparing the amount of acoustic output.

Humming Facilitates a Gradual Increase in Vocal Intensity by Alleviating the Enhancement of Vocal Fold Contact and Supraglottic Constriction.

OBJECTIVES: This study aimed to assess whether or not humming can help increase vocal intensity gradually with only a slight increase in the glottal contact and supraglottic compression. METHODS: Seventeen healthy nondysphonic speakers were asked to perform two phonatory tasks in order: gradually increasing vocal loudness (crescendo) during sustained phonation of a vowel or production of a hum (vowel- or humming-crescendo task: VCT or HCT, respectively), while the sound pressure levels (SPL), electroglottographic (EGG) signals and high-speed laryngeal movies were simultaneously recorded. The glottal contact parameter of the EGG signals and the glottal opening and laryngeal outlet parameters as well as the duration of prephonatory transient glottal closure on the laryngeal movies were calculated. RESULTS: With a gradual SPL increase during both tasks, most participants showed a progressive decrease in the LO, but no discernible change in the EGG glottal contact. In comparisons between tasks, an HCT produced a significantly lower SPL, greater laryngeal outlet parameter value and shorter prephonatory transient glottal closure duration than a VCT. A significant difference between tasks was found in the proportion of failed task performance due to an abrupt SPL increase (41% and 6% in VCT and HCT, respectively; P = 0.011), and the failed VCTs showed a significantly higher EGG contact parameter value than the successful VCTs. CONCLUSION: These results demonstrate that during an gradual increase in vocal intensity, humming alleviates the enhancement in both the glottal contact and supraglottic compression, leading to the prevention of an abrupt increase in vocal intensity instead of adequate vocal output.

Effects of vocal nodules on acoustic characteristics of voice in children†:†an acoustic analysis of voice.

Objective : In the present study, an attempt was made to evaluate the acoustic characteristics of voice in pediatric patients with vocal nodules using acoustic analysis of voice. Methods : Thirty-five pediatric patients with vocal nodules and 32 control children without dysphonia were enrolled in this study. Their voice samples were analyzed using the Multi-Dimensional Voice Program. Acoustic parameters of voice, such as pitch period perturbation quotient (PPQ), amplitude perturbation quotient (APQ), and noise-to-harmonic ratio (NHR), were measured. Results : In phonation at a loudness of over 80 dBA, the PPQ, APQ, and NHR values of the voice significantly increased in children with vocal nodules than in the control children without dysphonia. The sensitivities and specificities of PPQ, APQ, and NHR for prediction of vocal nodules in children were 62.86% and 84.38%, 74.29% and 75.00%, and 31.43% and 93.75%, respectively. Discussion : The present findings suggest that vocal nodules affect vocal fold vibration, resulting in impaired control of pitch and loudness leading to increased noise components. NHR could be used to evaluate the efficacy of treatment, such as voice rehabilitation, in pediatric patients with vocal nodules because of its high specificity for prediction of vocal nodules in children. J. Med. Invest. 68 : 276-279, August, 2021.

Intertext Variability of Smoothed Cepstral Peak Prominence, Methods to Control It, and Its Diagnostic Properties.

OBJECTIVES: This study aimed to estimate the intertext variability of smoothed cepstral peak prominence (CPPS), examine whether sound-processing techniques improved its variability and diagnostic capability, and evaluate the degree of intertext variability in detail with reference to the CPPS variabilities in sustained vowels. STUDY DESIGN: This was a retrospective study. METHODS: Text readings of 58 Japanese syllables were recorded from 210 speakers with different diagnoses and varying degrees of dysphonia, and were divided into six passages. Applying the sound-processing techniques to those passages, we prepared three sample types: (1) nonprocessed, (2) only-loud, and (3) only-voiced samples. The intertext CPPS variability and diagnostic properties were compared across the passages and sample types. For detailed analysis, we subsequently extracted 63 normophonic speakers who maintained constant quality in their vowel utterances to evaluate the degree of intertext CPPS variability in relation to the variabilities between repeated identical vowels and across different vowels. RESULTS: Although several combinations of passages showed moderate-to-large CPPS variabilities, those variabilities were decreased by either technique, especially the deletion of silent segments, which resulted in the best diagnostic accuracy. The degree of intertext CPPS variability for the only-voiced samples was comparable to that of the CPPS variabilities in sustained vowels. CONCLUSIONS: The sound-processing technique removing silent segments should be applied to enhance the diagnostic properties of CPPS. The additional technique of deleting unvoiced segments is worth adopting if clinicians and researchers seek to attenuate the influence of text differences in calculating CPPS values.

The Acoustic Voice Quality Index Version 03.01 for the Japanese-speaking Population.

OBJECTIVES: We aimed to determine the most appropriate syllable number for analyzing the Acoustic Voice Quality Index for the Japanese-speaking population (AVQIv3-JP) and to validate AVQIv3-JP using the determined syllable number. METHODS: First, we counted how many syllables should be included in each continuous speech (CS) sample to achieve time-balanced analysis between CS and sustained vowel samples using our previous dataset including 336 CS samples with 58 syllables. From the descriptive statistics of the counted syllable numbers, the most appropriate syllable number was identified. Subsequently, we performed validation procedures of AVQIv3-JP using our latest dataset including 455 recordings. RESULTS: Thirty Japanese syllables were judged to be the most appropriate syllable number. The concurrent validity of the AVQIv3-JP using 30 syllables was confirmed by Spearman's rho of 0.873. Subsequently, the receiver operating characteristic analysis demonstrated the excellent discriminative capability of AVQIv3-JP, showing the area under the curve of 0.915. The AVQIv3's original threshold of 2.43 in the Dutch language corresponded to sensitivity and specificity of 64.6% and 97.3%, respectively. In the present study, a threshold of 1.41 achieved the best accuracy with balanced sensitivity and specificity of 84.4% and 85.6%, respectively. Furthermore, the 95th percentile of the control participants exhibited a threshold of 2.06, showing sensitivity and specificity of 72.1% and 93.8%, respectively, as well as reasonable positive and negative likelihood ratios of 11.7 and 0.298, respectively. CONCLUSION: The AVQIv3 using 30 Japanese syllables is a reliable measurement tool for estimating the severity of voice quality and detecting abnormal voices.