Harmonics-to-noise Ratio Research Articles

Influence of age on voice quality after transoral CO2 laser microsurgery

ObjectiveTo study the post-operative evolution of voice quality of patients treated by transoral CO2 laser microsurgery (TLM) according to the age.MethodsPatients treated by type I to VI TLM and post-operative speech therapy were prospectively recruited from our hospital. The voice quality was assessed pre-, 1-, 3- 6- and 12-month posttreatment with voice handicap index (VHI), dysphonia, roughness, breathiness, asthenia, strain (GRBAS), maximal phonation time (MPT), F0, F0 standard deviation (STD), percent jitter, percent shimmer, noise-to-harmonic ratio (NHR), vocal fold vibration assessment and speech fluency. Evolution of voice outcomes was analyzed considering age of patients (< 60 vs. ≥ 60 years).ResultsSeventy-five patients completed the evaluations. Thirty-four and forty-one patients were < 60 or ≥ 60 yo, respectively. Subjective and objective voice parameters (VHI, G, R, B), jitter and fluency significantly improved from 1- to 6-month post-TLM in < 60 yo individuals. The voice parameters improved 12-month post-TLM in the ≥ 60 yo group at the exception of VHI that improved 3-month post-TLM. There were positive associations between age and 12-month NHR, G and A parameters.ConclusionThe post-operative evolution of voice quality parameters may vary between patients according to the age. Preoperative VHI is predictive of 12-month subjective and objective voice outcomes.Graphical abstract

Comparative Study of Harmonics to Noise Ratio of Closed Organ Pipe at First and Second Resonance

A sound wave has two components as periodic and non-periodic whose ratio is known as harmonic to noise ratio (HNR). HNR is an important parameter to analyze the voice. It also measures the degree of hoarseness. The measure of this parameter can be done with the help of Praat software. This paper compares the HNR of a closed organ pipe at first resonance and second resonance. HNR has varied from 10.95 dB to 27.87 dB at the first resonance and 7.3 dB to 23.87 dB at the second resonance. The average values at first and second resonance are 15.69 dB and 11.99 dB respectively. From the observation table and graph, it was found that HNR is greater at first resonance than second resonance for closed organ pipe.

Acoustic speech features in social comparison: how stress impacts the way you sound

The use of speech as a digital biomarker to detect stress levels is increasingly gaining attention. Yet, heterogeneous effects of stress on specific acoustic speech features have been observed, possibly due to previous studies’ use of different stress labels/categories and the lack of solid stress induction paradigms or validation of experienced stress. Here, we deployed a controlled, within-subject psychosocial stress induction experiment in which participants received both neutral (control condition) and negative (negative condition) comparative feedback after solving a challenging cognitive task. This study is the first to use a (non-actor) within-participant design that verifies a successful stress induction using both self-report (i.e., decreased reported valence) and physiological measures (i.e., increased heart rate acceleration using event-related cardiac responses during feedback exposure). Analyses of acoustic speech features showed a significant increase in Fundamental Frequency (F0) and Harmonics-to-Noise Ratio (HNR), and a significant decrease in shimmer during the negative feedback condition. Our results using read-out-loud speech comply with earlier research, yet we are the first to validate these results in a well-controlled but ecologically-valid setting to guarantee the generalization of our findings to real-life settings. Further research should aim to replicate these results in a free speech setting to test the robustness of our findings for real-world settings and should include semantics to also take into account what you say and not only how you say it.

Acoustic Feature Extraction Method of Rotating Machinery Based on the WPE-LCMV

Fault diagnosis plays an important role in the safe and stable operation of rotating machinery, which is conducive to industrial development and economic improvement. However, effective feature extraction of rotating machinery fault diagnosis is difficult in the complex sound field with characteristics of reverberation and multi-dimensional signals. Therefore, this paper proposes a novel acoustic feature extraction method of the rotating machinery based on the Weighted Prediction Error (WPE) integrating the Linear Constrained Minimum Variance (LCMV). The de-reverberation signal is obtained by inputting multi-channel signals into the WPE algorithm using an adaptive optimal parameters selection function with the sound field changes. Then, the incident angle going from the fault source to the center of the microphone array is calculated from the full-band sound field distribution, and the signal is de-noised and fused using the LCMV. Finally, the fault feature frequency is extracted from the fused signal envelope spectrum. The results of fault data analysis of the centrifugal pump test bench show that the Envelope Harmonic Noise Ratio (EHNR) is more than twice that of the original signal after the WPE-LCMV processing. Compared to the Recursive Least Squares and the Resonance Sparse Signal Decomposition (RLS-RSSD) and the parameter optimized Variational Mode Decomposition (VMD), the EHNR has a higher value for all types of faults after applying the WPE-LCMV processing. Furthermore, the proposed method can effectively extract the frequency of bearing faults.

Comparison of Acoustic Voice Features Derived From Mobile Devices and Studio Microphone Recordings

Improvements in mobile device technology offer new opportunities for remote monitoring of voice for home and clinical assessment. However, there is a need to establish equivalence between features derived from signals recorded from mobile devices and gold standard microphone-preamplifiers. In this study acoustic voice features from android smartphone, tablet, and microphone-preamplifier recordings were compared. Data were recorded from 37 volunteers (20 female) with no history of speech disorder and six volunteers with Huntington's disease (HD) during sustained vowel (SV) phonation, reading passage (RP), and five syllable repetition (SR) tasks. The following features were estimated: fundamental frequency median and standard deviation (F0 and SD F0), harmonics-to-noise ratio (HNR), local jitter, relative average perturbation of jitter (RAP), five-point period perturbation quotient (PPQ5), difference of differences of amplitude and periods (DDA and DDP), shimmer, and amplitude perturbation quotients (APQ3, APQ5, and APQ11). Bland-Altman analysis revealed good agreement between microphone and mobile devices for fundamental frequency, jitter, RAP, PPQ5, and DDP during all tasks and a bias for HNR, shimmer and its variants (APQ3, APQ5, APQ11, and DDA). Significant differences were observed between devices for HNR, shimmer, and its variants for all tasks. High correlation was observed between devices for all features, except SD F0 for RP. Similar results were observed in the HD group for SV and SR task. Biological sex had a significant effect on F0 and HNR during all tests, and for jitter, RAP, PPQ5, DDP, and shimmer for RP and SR. No significant effect of age was observed. Mobile devices provided good agreement with state of the art, high-quality microphones during structured speech tasks for features derived from frequency components of the audio recordings. Caution should be taken when estimating HNR, shimmer and its variants from recordings made with mobile devices.

Voice Therapy Efficacy in Pediatric Professional Voice Users With Vocal Fold Nodules: A Preliminary Study

Vocal fold nodules are the most common diagnosis in children with dysphonia. It is also frequently seen in professional voice users who uses their voice as an occupational tool. It can be caused by excessive or hyperfunctional use of the voice leading to phonotrauma. Children who learn the Quran by heart and recite it use their voices excessively and it causes voice problems. Voice therapy can play an important role in regulating phonotraumatic behaviors and improving voice quality, thereby replacing surgical intervention in some cases or acting as a complementary therapy to improve eventual therapeutic outcomes. Our aim was to find the efficacy of group voice therapy compared to individual voice therapy in a group of pediatric professional voice users who go to the same religious school. To determine group therapy efficacy, 24 students between the age of nine and 14, were evaluated and 16 of them had vocal fold nodules. Therapy sessions started with 16 students whose ages ranged from nine to 14 with a mean of 11,3 ± 1,4 years old. They were divided into two groups: group and individual therapy groups. Treatment comprised both direct and indirect voice therapy and lasted 6 weeks. Three of the participants were dropped out due to absence. Pre- and post-therapy measures were collected from 13 participants using perceptual evaluation, videostroboscopy measures, and the pediatric voice handicap index to determine the efficacy of group voice therapy compared to individual voice therapy with a group of pediatric professional voice users with vocal fold nodules. As a result of our study, eight of participants were found to have healthy vocal folds; the s/z ratio was significantly different between groups and within group therapy participants pre- and post-therapy. No significant difference was found in other parameters; except noise harmonic ratio (NHR). NHR was found significantly different between pre- and post-therapy when individual therapy and group therapy were compared. Although both treatments were shown to be beneficial in the management of vocal fold nodules, individual therapy was found to be somewhat more effective. In pediatric voice therapy, group therapy is an effective option to reach out to more individuals with voice disorders. It can be beneficial for time management and cost effectiveness in voice therapy.

Voice quality as an indicator of speaker's social information and as a cue for sound change

Voice quality reflects a variety of information in speech. The present study examines how voice quality may indicate a speaker's social information. We examine the ongoing /yø∼y/ merger in Shanghainese Wu. The first vowel formant (F1) and Harmonics-to-noise ratio (HNR) are extracted from 80 speakers. We also collect social information including age, gender, and immigrant background, family language, and working language. Mixed-effects linear regression models are built with the F1/HNR difference between /yø∼y/ as the dependent variable. Significant age effects are found on both F1 (β = 0.043, p = 0.006) and HNR (β = −0.055, p = 0.024); F1 is also more merged for female speakers than males (β = −0.521, p = 0.001); HNR is more distinct for speakers from non-immigrant families than speakers from immigrant families (β = 1.858, p = 0.008). The study shows a tendency for /yø∼y/ to merge in terms of both vowel quality and voice quality. It is noteworthy that speakers of native origin participate in the vowel-quality merging (cued by F1) but not in the voice-quality merging (cued by HNR). Taken together, voice quality can function as an independent indicator of a speaker’s social attributes.

Investigating the individual difference in distance calls of Bengalese finches using acoustic analysis

Most songbirds are monogamous and exhibit biparental care. They socially interact with other individuals, including those outside the family, through auditory modality. The capacity to explicitly identify conspecific individuals via acoustic cues enables fast turn-taking communication in a crowd, especially when visual signals are not available. Bengalese finches (Lonchura striata var. domestica) are domesticated strains of the white-rumped munia imported from China to Japan about 260 years ago. Previous studies have reported distance calls, which are emitted when a bird is visually separated from its conspecifics, are sexually dimorphic (both acoustically and perceptually) in Bengalese finches. However, the individuality in distance calls has not been thoroughly discussed yet. In this research, we recorded vocalizations from four pairs of Bengalese finches in kinship. To extract distance calls from those recordings, we use the Harmonics-to-Noise Ratio (HNR) to detect and remove noise, which mainly consists of aperiodic components. By analyzing acoustic features such as length, bandwidth, and peak frequency, we found that calls from the same individuals form clear clusters, and the difference between other individuals was more pronounced in contrast to kins. [Work supported by MEXT/JSPS grant #4903, 17H06380.]

CO2 transoral laser microsurgery for early glottic carcinoma with anterior commissure involvement

ObjectiveAnterior commissure (AC) involvement is an unfavorable factor for transoral laser microsurgery (TLM) treatment of early glottic carcinoma (EGC). This study aimed to evaluate the therapeutic efficacy of TLM treatment for EGC with AC involvement. MethodsFrom 2008 to 2017, 177 patients with T1-T2 EGC with AC involvement were retrospectively included and divided into the TLM group (n=115) receiving CO2 laser TLM and the control group undergoing open surgery (n=62). The survival outcomes, postoperative complications, laryngeal preservation rate, recurrence and the phonological results were compared between groups. ResultThe TLM group had significantly reduced hospital stay, hospitalization costs, and intraoperative blood loss as compared with the control group. The tracheotomy rate was significantly higher in the control group (96.8% vs. 0%). The 5-year overall survival (OS) was 89.6% and 85.5% in the TLM group and control group, respectively. Log-rank test showed no difference in survival rate between the two groups. There was no significant difference in laryngeal preservation rate and overall recurrence rate between groups. In postoperative vocal function evaluation, there were significant differences in the overall grade (G), the roughness (R), the breathiness (B), Voice Handicap Index-10 (VHI-10), Jitter, Shimmer, noise/harmonic ratio (NHR), maximum phonation time (MPT), phonation threshold pressure (PTP) between the two groups. ConclusionFor EGC with AC involvement, TLM has similar survival outcomes with the open surgery, but has better postoperative voice outcomes. Meanwhile, TLM can effectively reduce intraoperative blood loss, hospitalization time, hospitalization costs and postoperative complications.

Is There a Relationship between Voice Quality and Obstructive Sleep Apnea Severity and Cumulative Percentage of Time Spent at Saturations below Ninety Percent: Voice Analysis in Obstructive Sleep Apnea Patients.

Background and Objectives: Apnea hypopnea index is the most important criterion in determining the severity of obstructive sleep apnea (OSA), while the percentage of the total number of times which oxygen saturation is measured below 90% during polysomnography (CT90%) is important in determining the severity of hypoxemia. As hypoxemia increases, inflammation will also increase in OSA. Inflammation in the respiratory tract may affect phonation. We aimed to determine the effects of the degree of OSA and CT90% on phonation. Materials and Methods: The patients were between the ages of 18–60 years and were divided into four groups: normal, mild, moderate, and severe OSA. Patients were asked to say the vowels /α:/ and /i:/ for 5 s for voice recording. Maximum phonation time (MPT) was recorded. Using the Praat voice analysis program, Jitter%, Shimmer%, harmonics-to-noise ratio (HNR), and f0 values were obtained. Results: Seventy-two patients were included. Vowel sound /α:/; there was a significant difference for Jitter%, Shimmer%, and HNR measurements between the 1st and the 4th group (p < 0.001, p < 0.001, and p < 0.001, respectively) and a correlation between CT90% and Shimmer% and HNR values (p < 0.001 and p < 0.021, respectively). Vowel sound /i:/; there was a significant difference in f0 values between the 1st group and 2nd and 4th groups (p < 0.028 and p < 0.015, respectively), and for Jitter%, Shimmer%, and HNR measurements between the 1st and 4th group (p < 0.04, p < 0.000, and p < 0.000, respectively), and a correlation between CT90% and Shimmer% and HNR values (p < 0.016 and p < 0.003, respectively). The difference was significant in MPT between the 1st group and 3rd and 4th groups (p < 0.03 and p < 0.003, respectively). Conclusions: Glottic phonation can be affected, especially in patients whose AHI scores are ≥15. Voice quality can decrease as the degree of OSA increases. The increase in CT90% can be associated with the worsening of voice and can be used as a predictor in the evaluation of voice disorders in the future.

Tracking Occupational Voice State with a Visual Analog Scale: Voice Quality, Vocal Fatigue, and Effort.

Due to elevated vocal health risk in industries such as call centers, there is a need to have accessible and quick self-report tools for voice symptoms. This study aimed to determine if the concurrent and construct validity of three visual analog scales (VASs) of voice quality and symptoms could be used as a screening tool in call center agents. A cross-sectional study was carried out in three call center companies. The Voice Handicap Index-10 (VHI-10) and a vocal hygiene and symptoms survey were administered to 66 call center workers. Further, acoustic parameters including harmonics-to-noise ratio (HNR), smoothed cepstral peak prominence (CPPs), L1-L0 slope, and Alpha ratio were collected. Finally, workers completed three VASs capturing self-perception of vocal effort (VAS-1), voice quality (VAS-2), and vocal fatigue (VAS-3). Linear regression models with bootstrapping evaluated the possible relationship between the three VASs measurements, self-perceived vocal symptoms, and acoustic parameters. VAS-1 scores were associated with HNR and voice breaks, VAS-2 with voice breaks, and VAS-3 with Alpha ratio. Using the area under a receiver operating characteristic curve (AUC), the highest AUC for detecting an altered VHI-10 questionnaire score was observed for the three VASs. Also, the highest AUC for detecting altered CPPs was reached for the VAS-1. VAS as a self-report instrument of vocal symptoms is related to psychosocial voice impairment and alterations of acoustic voice parameters in call center workers. Such instruments could be easily implemented to identify voice complaints in these populations. 2 (Diagnosis research question) Laryngoscope, 133:1676-1682, 2023.

Increasing the speech intelligibility by the use of voice therapy in patients with profound hearing loss

Objective: The purpose of this study is to evaluate changes in the acoustic properties of voice in patients with profound sensorineural hearing loss to determine the effectiveness of voice therapy. Material-Method: Our study consisted of 15 individuals from the 20-25 years of age with bilateral symmetrical hearing loss (Group A), and 15 individuals in the 26-65 age group with post lingual cochlear implants (Group B). The control group (Group C) included 15 adults with the normal hearing range from the age group of 20-30. Prospective analysis methods was utilized for this research. In order to quantitatively measure the psychosocial consequences of voice-related disorders the Voice Handicap Index (VHI) was given, and, to determine the acoustic measures of the voice quality, the /ah/ sound was digitally recorded with the Multidimensional Voice Program (Kay Elemetrics) in all groups. Conclusion: Average Fundamental frequency (F0), jitter percentage (jitter), shimmer, noise-harmonic ratio (NHR), voice turbulence index (VTI), soft phonation index (SPI), PPQ and APQ parameters were analyzed through acoustic sound analysis program. When the data in Group A are compared with Group B, the acoustic parameters show a statistically significant higher value. Discussion: Speech intelligibility increased in individuals with profound hearing loss who received sound therapy and who used cochlear implants. According to the results of the VHI, individuals with cochlear implants benefit from voice therapy.

Impact of Pulmonary Function on Voice Outcomes After Injection Laryngoplasty for Unilateral Vocal Fold Paralysis

Pulmonary function is closely associated with voice quality especially in patients with voice disorder including unilateral vocal fold paralysis (UVFP). Injection laryngoplasty (IL) is the standard treatment for patients with UVFP. We investigated the subjective and objective voice outcomes according to pulmonary function test (PFT) before IL in patients with UVFP. We retrospectively analyzed the patients who underwent IL for UVFP between 2004 and 2021 (N = 1201), and finally investigated 261 patients with PFT results before IL. The patients were classified into three groups according to results of PFT: normal (n = 189, 72%), mild (n = 40, 15%), and moderate (n = 32, 13%) obstructive pattern. Aspiration symptoms and subjective and objective voice parameters of voice handicap index (VHI), GRBAS score, maximal phonation time (MPT), Jitter, Shimmer, and noise to harmonic ratio (NHR) were compared between normal and abnormal (mild or moderate obstructive pattern) PFT groups. Age (68.0 ± 9.1 and 61.2 ± 12.6, respectively) was significantly higher and males were more common (84.7% and 57.7%, respectively) in abnormal PFT than in normal PFT. Aspiration showed significant improvement in all groups. The subjective and objective voice parameters significantly improved after IL in normal and mild obstruction groups, but MPT, Shimmer, and VHI did not significantly improve in the moderate obstruction group. The improvement in VHI-30 after IL was significantly higher in the normal group (20.0 ± 29.5) than in the mild (10.3 ± 32.8) or moderate (9.9 ± 33.2) obstruction group (P = 0.035). Improved amounts of MPT, Jitter, Shimmer, and NHR were not significantly different among the groups, but improvement of VHI was smallest in the moderate obstructive pattern group. Voice parameters showed significant improvement after IL in both normal and mild obstructive pattern groups, but MPT and VHI did not significantly improve in the moderate obstructive pattern group. In addition, patients with normal pulmonary function had marked improvement of subjective symptoms after IL in comparison with patients with abnormal pulmonary function.

Harmonics-to-noise ratio estimation with deterministically time-varying harmonic model for pathological voice signals.

The harmonics-to-noise ratio (HNR) and other spectral noise parameters are important in clinical objective voice assessment as they could indicate the presence of nonharmonic phenomena, which are tied to the perception of hoarseness or breathiness. Existing HNR estimators are built on the voice signals to be nearly periodic (fixed over a short period), although voice pathology could induce involuntary slow modulation to void this assumption. This paper proposes the use of a deterministically time-varying harmonic model to improve the HNR measurements. To estimate the time-varying model, a two-stage iterative least squares algorithm is proposed to reduce model overfitting. The efficacy of the proposed HNR estimator is demonstrated with synthetic signals, simulated tremor signals, and recorded acoustic signals. Results indicate that the proposed algorithm can produce consistent HNR measures as the extent and rate of tremor are varied.

언어재활사의 주관적 음성피로도와 관련된 음향적 특성*

In addition to administering a questionnaire (J-survey), which questions individuals on subjective vocal fatigue, voice samples were collected before and after speech-language pathology sessions from 50 female speech-language pathologists in their 20s and 30s in the Daejeon and Chungnam areas. We identified significant differences in Korean Vocal Fatigue Index scores between the fatigue and non-fatigue groups, with the most prominent differences in sections one and two. Regarding acoustic phonetic characteristics, both groups showed a pattern in which low-frequency band energy was relatively low, and high-frequency band energy was increased after the treatment sessions. This trend was well reflected in the low-to-high ratio of vowels, slope LTAS, energy in the third formant, and energy in the 4,000-8,000 Hz range. A difference between the groups was observed only in the vowel energy of the low-frequency band (0-4,000 Hz) before treatment, with the non-fatigue group having a higher value than the fatigue group. This characteristic could be interpreted as a result of voice abuse and higher muscle tonus caused by long-term voice work. The perturbation parameter and shimmer local was lowered in the non-fatigue group after treatment, and the noise-to-harmonics ratio (NHR) was lowered in both groups following treatment. The decrease in NHR and the fall of shimmer local could be attributed to vocal cord hypertension, but it could be concluded that the effective voice use of speech-language pathologists also contributed to this effect, especially in the non-fatigue group. In the case of the non-fatigue group, the rhamonics-to-noise ratio increased significantly after treatment, indicating that the harmonic structure was more stable after treatment.

Acoustic Voice Measures in Benign Mass Lesions

Objectives: The present study aims to compare acoustic voice parameters in patients with vocal cord nodules, polyps, and normal subjects. Methods: In this cross-sectional case-control study, the participants were selected by convenience sampling, including 30 patients with vocal polyps for the first group, 38 patients with vocal nodules for the second group, and 42 participants without voice pathologies as the control group. For each group, participants were examined by a speech and language pathologist (SLP) using an Endo-vision laryngoscope. Acoustic voice parameters were measured by MDVP software in Visi-Pitch; then, these parameters were compared in groups in terms of sex. Results: Three groups showed significant differences in terms of fundamental frequency (P&lt;0.001), jitter (P&lt;0.001), shimmer (P&lt;0.001), and noise-to-harmonic ratio (NHR) values (P&lt;0.001). Women in three groups had the substantial differences in terms of fundamental frequency (P&lt;0.001), jitter (P&lt;0.001), shimmer (P&lt;0.001), and NHR (P&lt;0.001). For men, the three groups showed a significant difference for jitter (P&lt;0.001) and shimmer (P=0.001), but for NHR (P=024), and fundamental frequency (P=0.93) no signification difference were observed. Discussion: It seems that the existence of benign mass lesions, such as vocal cord nodules and polyps affects the acoustic parameters of the voice. The measurement of acoustic voice parameters may help us to differentiate between the voices of normal people and patients with vocal cord nodules and polyps as a supplementary assessment in clinical procedures.

Objective and subjective voice evaluation in Covid 19 patients and prognostic factors affecting the voice

Coronavirus disease 2019 (COVID-19), a respiratory and systemic zoonosis form caused by a virus belonging to the Coronaviridae family. Although several studies have shown the otolaryngology symptoms are affected in COVID-19 patients, the number of studies regarding the COVID-19 effects on voice is limited. Our study aims to evaluate the effect of COVID-19 on voice objectively - subjectively and compare it with the control group. 50 hospitalized patients with laboratory-confirmed COVID-19 and 50 healthy individuals were included in the study as study and control group, respectively. All subjects were trained to vocalize a continuous/a/ vocal pattern at speech sound intensity for Maximum Phonation Time. Voice samples were recorded using a Sony (ICD-PX470) audio recorder and analyzed by the Praat program. Dysphonia grades were ranked on 4-point scales (grade: 0=none; 1= mild; 2= moderate; 3=severe). It is seen from the results that, there were significant differences between the male and female participants in acoustic parameters of fundamental frequency (F0) (p&lt;0.001), shimmer and mean harmonic to noise ratio (HNR) (p=0.011). There was also a significant difference in F0 values of infected and healthy participants (p=0.008). However, there was no significant interaction between gender and health status in any acoustic parameters (p&gt;0.05). The degree of thoracic computed tomography (CT) involvement had no significant effect on parameters (p&gt;0.05), while there was a weak positive relationship between the duration of hospitalization and F0 (rs=0.397, p=0.004). Dysphonia was positively associated with health status (rs=0. 682, p&lt;0.001), and female infected participants reported more frequent dysphonia than males. In our study, we examined the effect of COVID-19 on voice both objectively and subjectively and evaluated the relationship between CT involvement and duration of hospitalization, which made our study more reliable. Future studies with larger and more specific patient groups to investigate the relationship between COVID-19 and dysphonia will shed a light on the subject.

Validity of intraoperative voice monitoring undergoing type 2 thyroplasty with titanium bridges for adductor spasmodic dysphonia.

ObjectivesThe success of type 2 thyroplasty (TP2) for adductor spasmodic dysphonia (AdSD) depends on the selection of optimally sized titanium bridges, which requires accurate assessment of intraoperative vocal changes. While this procedure has traditionally been performed according to the laryngologist's experience, the most appropriate method for voice monitoring and selection of titanium bridge size remains to be determined. This study aimed to investigate evaluation parameters useful for voice monitoring, as these may allow less experienced surgeons to perform TP2 properly.MethodsIn this prospective study, voice monitoring was performed in 18 patients with AdSD patients undergoing TP2. Evaluations were performed preoperatively, intraoperatively, 13 weeks postoperatively, and 52 weeks postoperatively using GRBAS (grade, roughness, breathiness, asthenia, and strain), as well as perceptual judgment and acoustic analyses.ResultsPreoperative and intraoperative assessments of the G, R, B, and S parameters, perceptual judgment, and harmonic‐to‐noise ratio (HNR) were in moderate or better agreement. Intraoperative and 13‐ or 52‐week postoperative measurements of the R, B, and G parameters and strangulation, tremor, and HNR were also in high agreement. When two different sizes of titanium bridges were compared (unselected vs. selected), ratings for G, R, S, strangulation, tremor, jitter, shimmer, HNR, standard deviation of F0, and degree of voice breaks were better for the selected width than the unselected width.ConclusionThe candidate items for intraoperative voice monitoring during TP2 for AdSD are G, R, strangulation, tremor, and HNR. The use of these items may help to ensure successful TP2 and contribute to the advancement of laryngeal framework surgery.Level of evidenceLevel 4.

The Effect of Bilevel Positive Airway Pressure on Voice Quality

Inflammation of the upper airways, thickening of the lateral pharyngeal walls, elongation of the soft palate and uvula, hypertrophy of the tonsils and base of the tongue can be seen in obstructive sleep apnea syndrome patients. Changes in these structures may affect articulation and phonation, negatively affecting the quality of the voice. Positive airway pressure (PAP) treatment reduces the volume of the root of the tongue, dissolves the edema in the upper respiratory tract, increases the posterior pharyngeal area, and positively changes the quality of the voice. A total of 151 people, 50 control group, and 101 patients, were included in the study between December 2020 and December 2021. The patient group was divided into two groups as continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BPAP) users. All voice recordings were made in the control group and the patient group before and 3 months after CPAP and BPAP treatment, and were evaluated with the Praat (Paul, 2001) voice analysis program. The fundamental frequency of the sound (F0), frequency perturbation (jitter), amplitude perturbation (shimmer), noise-to-harmonic ratio (NHR) values were evaluated in the patient and control groups, and they were compared with each other before and after the treatment in the CPAP and BPAP groups. Before and after PAP treatment; the changes in F0, Jitter, Shimmer, and NHR in the CPAP and BPAP group were statistically significant (P < 0.05). While the F0 change before and after PAP treatment was the most in the CPAP group, the jitter, shimmer and NHR changes were the most in the BPAP group. Regular 3-month PAP treatment positively affects F0, jitter, shimmer and NHR values. The greatest F0 change is in the use of CPAP, the improvement in jitter, shimmer and NHR is the most in the use of BPAP.

Effects of the Orthognathic Surgery on the Voice Characteristics of Skeletal Class III Patients.

To analyze the effects of the bimaxillary orthognathic surgery on the voice characteristics of skeletal Class III cases, and to evaluate correlations between acoustic and skeletal changes. Skeletal Class III adult patients (7 male, 18 female) were asked to pronounce the sounds "[a], [ɛ], [ɯ], [i], [ɔ], [œ], [u], [y]" for 3 seconds. Voice records and lateral cephalometric x-rays were taken before the surgery (T0) and 6 months after (T1). Voice records were taken for the control group with 6 months of interval (n=20). The formant frequencies (F0, F1, F2, and F3), Shimmer, Jitter and Noise to Harmonic Ratio (NHR) parameters were considered with Praat version 6.0.43. In the surgery group, significant differences were observed in the F1 of [e], F2 and Shimmer of [ɯ] and F1 and F2 of [œ] and F1 of [y] sound, the post-surgery values were lower. F3 of [u] sound was higher. In comparison with the control group, ΔF3 of the [ɔ], ΔF3 of the [u] and ΔF1 of the [y] sound, ΔShimmer of [ɛ], [ɯ], [i], [ɔ], [u] and [y], and the ΔNHR of [ɔ] sound significantly changed. The Pearson correlation analysis proved some correlations; ΔF2 between ΔSNA for [ɯ] and [œ] sounds, ΔF1 between ΔHBV for [y] sound. Bimaxillary orthognathic surgery changed some voice parameters in skeletal Class III patients. Some correlations were found between skeletal and acoustic parameters. We advise clinicians to consider these findings and inform their patients.