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.

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.

[Endoscopic sinus surgery for a paranasal sinuses mucocele with light guide and dacryoendoscopy].

It is hard to cure dacryocystitis caused by a paranasal sinus mucocele with treatment which only targets the mucocele. Also, it is difficult to identify the lacrimal sac and the nasolacrimal duct preoperatively and intraoperatively when the lacrimal passage is markedly changed by the mucocele or previous surgery. We experienced four cases of mucocele complicated by lacrimal stenosis or obstruction. We performed marsupialization of the mucocele and direct silicon intubation or endoscopic dacryocystorhinostomy simultaneously with the use of a fiberoptic illuminator or dacryoendoscopy. Assisted by those devices, lacrimal procedures can now be done quickly and safely regardless of the surgeon's experience. In addition, performing surgeries both for the lacrimal passage and for the mucocele at the same time can minimize the burden on patients.

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.

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.

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.

Acoustic Breathiness Index for the Japanese-Speaking Population: Validation Study and Exploration of Affecting Factors.

Objectives The purposes of this study were to validate the Acoustic Breathiness Index (ABI) for the Japanese-speaking population and to determine whether it is independent of factors such as sex, age, and perceptual ratings of roughness. Method First, the concurrent validity of the ABI for perceptual breathiness was evaluated on the concatenations of continuous speech and sustained vowels from 288 patients with varying degrees of dysphonia. The diagnostic accuracy was examined on 343 samples with 55 additional normophonic speakers. Second, the validity related to responsiveness-to-change was estimated on 222 samples obtained before and after interventions for 111 voice-disordered patients. Third, the relationships between the ABI and other variables (i.e., perceptual hoarseness/breathiness/roughness, sex, and age) were explored using bivariate and multivariate analyses for the 288 patients. Results First, the concurrent validity and the responsiveness-to-change validity were confirmed by strong correlation coefficients of .890 and .878, respectively. Second, the receiver operating characteristic analysis showed the area under the curve to be 0.939, indicating excellent accuracy. The ABI of 3.44 exhibited a sensitivity of 76.3% and a specificity of 94.1%. Third, although bivariate analyses revealed a weak relationship between ABI and roughness and an ABI difference by age, multiple regression analyses showed a strong relation between only ABI and breathiness, without a meaningful contribution from roughness, sex, and age factors. Conclusion The study confirmed that the ABI is an accurate and specific tool to estimate breathiness levels in the Japanese-speaking population and neither roughness, sex, nor age significantly affects the ABI.

The Effects of Humming on the Prephonatory Vocal Fold Motions Under High-Speed Digital Imaging in Nondysphonic Speakers.

OBJECTIVES: This study aimed to investigate whether humming affects the adductive motion of the vocal folds and transient glottal closure in the prephonatory adjustment phase of vocal onset using high-speed digital imaging (HSDI) and a motion analysis software program. METHODS: Twenty normal healthy adults without any vocal abnormalities were enrolled. While a transnasal flexible fiberscope connected to a high-speed camera was inserted, each participant was asked to perform three phonatory tasks-natural /e:/ phonation, loud /e:/ phonation, and humming /m:/ phonation-and laryngeal HSDI movies (4000 frame/s) were recorded. On each HSDI movie, the duration of the prephonatory glottal closure was measured. In addition, using motion analysis, the changes in the angle between the bilateral vocal folds during vocal fold adduction and the average angular velocity in the ranges of 100%-80%, 80%-20%, and 20%-0% from all of the angular changes were analyzed. RESULTS: The angular changes showed sigmoid and polynomial-like curves during the natural/humming and loud phonation, respectively, and the 80%-20% and 20%-0% average velocities were the highest during the natural/humming and loud phonation, respectively. The humming phonation decreased all of the average regional velocities, eliminated the transient prephonatory glottal closures observed during the natural and loud phonation, and induced a greater value for the minimal angle than the natural phonation. CONCLUSIONS: The present study demonstrates that humming encourages easy vocal initiation by decelerating the vocal fold adductive motion throughout the prephonatory adjustment phase and alleviating transient prephonatory laryngeal closure, leading to gradual and smooth vocal fold positioning.

Investigation of the Immediate Effects of Humming on Vocal Fold Vibration Irregularity Using Electroglottography and High-speed Laryngoscopy in Patients With Organic Voice Disorders.

OBJECTIVES: The study aimed to investigate whether humming can immediately improve the regularity of vocal fold vibration on electroglottography (EGG) and laryngeal high-speed digital imaging (HSDI) in patients with organic dysphonia (OD). METHODS: In a series of 49 dysphonic patients who were diagnosed to have benign mass lesions in the vocal folds and an equal number of non-dysphonic speakers, perturbation parameters were calculated on the acoustic (Ac) and EGG signals during natural and humming phonation. In addition, 11 OD patients and as many non-dysphonic speakers underwent simultaneous EGG and HSDI video recording under laryngofiberscopy while performing the two tasks. The perturbation parameters of the EGG signals as well as the glottal area waveforms (GAW), which were extracted from the HSDI movies, were calculated, and the correlations between both perturbation parameters were analyzed. RESULTS: Humming achieved significant improvements in the EGG perturbation parameters in both groups. More than half of the OD patients showed decreased EGG perturbation parameters to the level of those during natural phonation in the control group. With respect to the GAW analysis, moderate correlations were observed between both period and amplitude perturbation parameters (period: r = 0.63, amplitude: r = 0.41). Humming decreased both GAW perturbation parameters significantly in the OD and control subjects combined. CONCLUSIONS: These results demonstrate that in OD patients, humming has a potential to improve voice quality by stabilizing the vocal fold oscillation, and suggest that humming can remove the functional component in the vocal disturbance instead of the mechanical effect of the mass lesions.

Validation of the Acoustic Voice Quality Index in the Japanese Language.

OBJECTIVES: The Acoustic Voice Quality Index (AVQI) is a multivariate construct for quantification of overall voice quality based on the analysis of continuous speech and sustained vowel. The stability and validity of the AVQI is well established in several language families. However, the Japanese language has distinct characteristics with respect to several parameters of articulatory and phonatory physiology. The aim of the study was to confirm the criterion-related concurrent validity of AVQI, as well as its responsiveness to change and diagnostic accuracy for voice assessment in the Japanese-speaking population. STUDY DESIGN: This is a retrospective study. METHODS: A total of 336 voice recordings, which included 69 pairs of voice recordings (before and after therapeutic interventions), were eligible for the study. The auditory-perceptual judgment of overall voice quality was evaluated by five experienced raters. The concurrent validity, responsiveness to change, and diagnostic accuracy of the AVQI were estimated. RESULTS: The concurrent validity and responsiveness to change based on the overall voice quality was indicated by high correlation coefficients 0.828 and 0.767, respectively. Receiver operating characteristic analysis revealed an excellent diagnostic accuracy for discrimination between dysphonic and normophonic voices (area under the curve: 0.905). The best threshold level for the AVQI of 3.15 corresponded with a sensitivity of 72.5% and specificity of 95.2%, with the positive and negative likelihood ratios of 15.1 and 0.29, respectively. CONCLUSIONS: We demonstrated the validity of the AVQI as a tool for assessment of overall voice quality and that of voice therapy outcomes in the Japanese-speaking population.

The results of Kaplan-Meier and multivariate analyses of etiological factors related to the outcome of combined pharmacological therapy against laryngeal granuloma.

CONCLUSIONS: The present results indicate that the diagnosis of gastroesophageal reflux disease (GERD) is an independent etiological factor predicting retardation of the resolution of laryngeal granuloma. OBJECTIVES: To assess the effects of combined usage of an inhaled corticosteroid plus tranilast and/or a proton pump inhibitor on the size of granulomatous lesions, and to reveal etiological factors related to the outcome using the Kaplan-Meier method and a subsequent multivariate analysis. METHODS: Sixty-two patients with laryngeal granuloma were enrolled. An inhaled corticosteroid plus tranilast (300 mg/day) and rabeprazole (20 mg/day) were administered to all of the patients, and only to those diagnosed to have GERD, respectively. The size of granulomatous lesion was measured for each patient at the initial visit and every 4 weeks. At 48 weeks, the Kaplan-Meier plots for lesion disappearance rate were compared between groups with and without each of the etiological factors, followed by Cox proportional-hazards regression. RESULTS: The 48-week lesion disappearance rates for the whole population were 82.3%. Although the Kaplan-Meier analysis exhibited significant differences between patients separated by GERD diagnosis, phonotrauma, and habitual smoking, only GERD were identified as a real independent etiological factor affecting the resolution of the lesion by a multivariate analysis using Cox's proportional-hazards regression.

A Detailed Motion Analysis of the Angular Velocity Between the Vocal Folds During Throat Clearing Using High-speed Digital Imaging.

OBJECTIVES: To assess the angular velocity between the vocal folds just before the compression phase of throat clearing (TC) using high-speed digital imaging (HSDI) of the larynx. METHODS: Twenty normal healthy adults (13 males and seven females) were enrolled in the study. Each participant underwent transnasal laryngo-fiberscopy, and was asked to perform weak/strong TC followed by a comfortable, sustained vowel phonation while recording an HSDI movie (4000 frames/s) of the larynx. Using a motion analysis, the changes in the vocal fold angle and angular velocity during vocal fold adduction were assessed. Subsequently, we calculated the average angular velocities in the ranges of 100-80%, 80-20%, and 20-0% from all of the angular changes. RESULTS: The motion analysis demonstrated that the changes in the angular velocity resulted in polynomial-like and sigmoid curves during TC and vowel phonation, respectively. The angular velocities during weak TC were significantly higher in the 20-0%, 80-20%, and 100-80% regions (in order); the 80-20% angular velocity in vocal fold adduction during phonation was highest. The 20-0% angular velocity during strong TC was more than twofold higher than 20-0% angular velocity during phonation. CONCLUSIONS: The present results confirmed that the closing motions of the vocal folds accelerate throughout the precompression closing phase of a TC episode, and decelerate just before the impact between the vocal folds at the onset of phonation, suggesting that the vocal fold velocity generated by TC is sufficient to damage the laryngeal tissues.

Computed tomographic assessment of the causal factors of unsuccessful medialization thyroplasty.

CONCLUSION: The present results demonstrate that a small implant size, undercorrection of the vocal fold, antero-posterior implant malposition, and the use of expanded polytetrafluoroethylene (ePTFE) are the primary factors that cause a poor outcome of medialization thyroplasty (MT). OBJECTIVES: To assess the postoperative laryngeal condition using computed tomography (CT) in patients with unilateral vocal fold paralysis who underwent MT alone, and to identify the primary causal factors in terms of the surgical procedures that affect the outcomes of MT. METHODS: Twenty-two patients who underwent MT alone were divided into two groups based on either the maximal phonation time or the perceived vocal breathiness. Two laryngologists assessed the postoperative laryngeal CT images during sustained vowel phonation and judged whether there were abnormalities of the arytenoid cartilage position, window position, implant size, and implant position, as well as the degree of correction of the vocal fold. As implant material, a silicone block, ePTFE, and hydroxyapatite had been inserted in 2, 9, and 11 patients, respectively. Comparisons of the prevalence of abnormalities in the abovementioned factors between the different outcomes and between the types of material used for the implant were performed. RESULTS: Twelve patients with a poor outcome and 10 with a good outcome showed 36 and 18 abnormal findings identified by either of the two laryngologists, respectively. In the poor outcome group, a smaller implant size and undercorrection of the vocal fold showed both high kappa values and a significantly higher prevalence than those in the good outcome group (p < 0.001 and p < 0.05), respectively. The comparison between material types demonstrated that the sheet-like material (ePTFE) group exhibited a significantly higher prevalence of undercorrection than the block-like material group (p < 0.05).

Does Cervical Muscular Contraction Affect the Measurement for Electroglottographic Perturbation Parameters?

OBJECTIVES: The purpose was to assess whether cervical muscular contraction during phonation influences the period and amplitude perturbation quotients (PPQ and APQ, respectively) of electroglottographic (EGG) signals, and whether high-pass filtering can attenuate these effects. STUDY DESIGN: Prospective. METHODS: We included 19 nondysphonic speakers and 21 patients with muscle tension dysphonia. During the recording of acoustic and EGG signals, each participant was instructed to naturally phonate sustained vowels /i:/ and /a:/ (NP tasks), and additionally, each nondysphonic participant was asked to phonate the same vowels in a nondysphonic voice quality while contracting the cervical muscles (muscular contracted phonation [MCP] tasks). To confirm the contraction, surface and needle electromyography (EMG) was performed. The EGG signals were high-pass filtered at different cutoff frequencies from 0 to 90 Hz and were subsequently analyzed for the PPQ and APQ. RESULTS: Compared with the NP tasks, the MCP tasks enhanced the cervical EMG activities ranging from 0 to more than 1000 Hz, but conferred only low-frequency noise to the EGG signals under 50 Hz and increased the values for EGG-APQ, but not EGG-PPQ. These EGG-APQ values exhibited gradual decreases after high-pass filtering with an increase in the cutoff frequency ranging from 0 to 50 Hz in both groups, followed by plateaus during the MCP tasks in the nondysphonic group. CONCLUSIONS: The present results demonstrate that cervical muscular contraction seriously affects the EGG-APQ values for unfiltered EGG signals independent of the EMG activities and that appropriate high-pass filtering over 50 Hz can attenuate these effects.

Immediate effects of humming on computed electroglottographic parameters in patients with muscle tension dysphonia.

OBJECTIVES: To investigate the immediate effects of humming and subsequent um-hum phonation on the computed parameters of electroglottographic (EGG) signals in muscle tension dysphonia (MTD) patients and nondysphonic speakers. METHODS: We included 21 MTD participants exhibiting both vocal roughness and supraglottic compression, who were able to produce successful humming and um-hum phonation. Twenty nondysphonic participants were selected as controls. Each participant was instructed to perform three phonatory tasks: natural phonation, humming phonation without pitch changes, and subsequent um-hum phonation, that is, humming with a pitch glide up as if agreeing with someone. Acoustic and EGG signals were recorded while the participants performed these tasks. Computed parameters reflecting the irregularities in vocal fold vibrations and the degree of glottal contact were calculated and compared between the tasks. RESULTS: The MTD group showed decreases in both perceptual vocal roughness and acoustic perturbation parameters while performing the tasks. The perturbation parameters of EGG signals and the standard deviation of the contact quotient (CQ) also exhibited significant decreases associated with either of humming or um-hum phonation in both groups. In addition, the CQ exhibited significant increases following humming alone in the MTD group and the combination of humming and um-hum phonation in both groups. CONCLUSIONS: These results suggest that the combination of humming without pitch changes and subsequent um-hum phonation have the immediate effect in adjusting the regularity of vocal fold vibration and augmenting the degree of glottal contact in MTD patients as well as nondysphonic speakers, whereas humming alone increases the degree of glottal contact in MTD patients.