Objective Acoustic Parameters Research Articles

Study of soundscapes in heritage festivals: the "Fallas" of Valencia, "Festa de la Mare de Déu d'Algemesí" and the "Moros y Cristianos" festival of Villena (Alicante)

The conservation of the Intangible Cultural Sound Heritage of Humanity is one of the most important assets of a people as it is linked to its culture and history. Its evaluation by means of objective acoustic and psycho-acoustic parameters makes it possible to characterise these environments from objective, aesthetic and emotional criteria. The description of the soundscape is governed by the ISO 12913 standard. The procedure for assessing soundscapes in outdoor sites is carried out with sound-walks. In this work, we have evaluated two different soundscapes in festivities in Spain: "Fallas" in Valencia, "Festa de la Mare de Déu" in Algemesí and "Moros y Cristianos" in Villena. This evaluation has been carried out by recording the ambient sound of these festivities while walking among people. From the recordings, we calculated different psychoacoustic metrics (i.e. loudness, sharpness, roughness, fluctuation stress and tonality) and evaluated them with Zwicker models. In addition, a subjective survey was conducted to compare the subjective response with the psychoacoustic metrics.

Articulation distortion in Mandarin-speaking individuals with complete arch maxillary implant-supported fixed dental prostheses

Implant-supported fixed dental prostheses (IFPs) have been increasingly used to restore edentulous jaws, yet few studies have utilized acoustic analysis for objective evaluation of postrestoration speech outcomes. The purpose of this clinical study was to assess speech articulation in edentulous individuals before and after the provision of IFPs by combining the results of subjective evaluations and objective acoustic analysis parameters. The study included thirty-four individuals who had an edentulous maxilla and had been provided with an IFP for over 6 months, along with 6 dentate controls. Acoustic analysis was conducted, and mean opinion scores (MOS) were rated from recordings. The participants were interviewed about perceived speech changes. Changes in the parameters were evaluated using the paired t test or Wilcoxon signed-rank test (α=.05). A comparison between dentate controls and edentulous individuals (with or without prostheses) was made using an independent t test or Mann-Whitney U test (α=.025). Following restoration, the center of gravity (CoG) changes occurred in 11 of 12 consonants in edentulous individuals (P<.05). Prosthesis use allowed the CoG of all affricates and fricatives to appear larger and closer to control values. Before restoration, the CoG of 9 of 12 consonants in edentulous individuals differed from controls (P<.01); after restoration, this reduced to 3 out of 12 (P<.01). MOS improved in 10 of 12 consonants (P<.01), nearing a score of 4. Despite restoration, the CoG of alveolo-palatals [tɕh], [tɕ], and [ɕ] remained different from controls (P<.01). Most participants were satisfied with the improvement, with few reporting discomfort with alveolars [s] and [tsh]. IFPs can enhance speech in edentulous individuals, yet articulation distortions of alveolar and alveolo-palatal consonants persist. The improper palatal shape of IFPs or an abrupt joint between the IFP and atrophic natural bone may contribute to these distortions.

Singing in different performance spaces: The effect of room acoustics on singers' perception.

Classical singers' performances vary across different acoustic environments. The changes in the delivery are influenced by the singer's perception of the venue's acoustics. This study investigated these relationships using nine professional or semi-professional classical singers. Participants performed Giordani's "Caro mio ben" aria in five venues, and the acoustic parameters reverberance (T30 and EDT), clarity (C80), early vocal support (STv), and tonal color (EDTf) were measured. From a factor analysis of the subjective analysis three major factors emerged that, we propose, would represent three generalized percepts of Room Supportiveness, Room Noiselessness, and Room Timbre. These percepts correlated significantly with objective acoustic parameters traditionally linked to vocal support, reverberation, and timbre. Room Supportiveness and Room Noiselessness significantly contributed to the singers' likability of the acoustic environment, while Room Timbre did not. This indicates that singers' perceptual preference for a performance space may be influenced by factors affecting both auditory feedback and vocal function. These findings underscore the need for performing space designers to consider the unique needs of all stakeholders, including listeners and performers. The study contributes to the bridging of the gap between subjective perceptions and objective measurements, providing valuable insights for acoustic design considerations.

Analysis of Sound Field Distribution in Architecturally Diverse Temples

The results of the research, which aimed to analyze the acoustic properties of selected sacred buildings located in the city of Czestochowa, Poland are presented in the paper. Three architecturally unusual and completely different from each other churches were selected for the study. The churches differed in shape of their buildings, cubic volume, years of construction, interior furnishings, etc. Nine different objective parameters were used to describe the physical properties of acoustical field in the studied churches. Various factors characterizing the acoustic properties of each building were determined, such as the distribution of sound pressure level (SPL), reverberation time T30, definition D50. Next, they were thoroughly analyzed, so as to ultimately obtain distributions of individual acoustic parameters in the space of the tested building. It allowed to evaluate the quality of the received verbal or musical message depending on the place where the listener was. Further research on speech intelligibility and the musical quality of churches was performed by determining the averaged values of next four objective acoustic parameters: centre time Ts, speech clarity C50, music clarity C80, and speech transmission index (STI). A new approach to analyzing the objective physical parameters describing the sound field was presented in Sec. 4. Mean free path length and critical distance were determined for the investigated acoustic fields in each church and they were associated with a general geometric factor characterizing the complexity of the room shape. The final part of the work presents a comparative analysis of the obtained results of acoustic quality tests of the temples, and thus their usefulness in terms achieving a maximum intelligibility of speech and music. The interesting similarities were found in the spatial distribution of individual acoustic parameters characterizing the distribution of the acoustic field in temples with completely different architecture.

Subjective and Objective Evaluation of Speech in Adult Patients With Repaired Cleft Palate.

To explore the speech outcomes of adult patients with repaired cleft palate through subjective perception evaluation and objective acoustic analysis, and to compare the differences in pronunciation characteristics between speakers with complete velopharyngeal closure (VPC) and velopharyngeal insufficiency (VPI) patients. Subjective evaluation indicators included speech intelligibility, nasality and consonant missing rate, for objective acoustic analysis, we used speech sample normalization and objective acoustic parameters included normalized vowel formants, voice onset time and the analysis of 3-dimensional spectrogram and spectrum, were carried out on speech samples produced by 3 groups of speakers: (a) speakers with velopharyngeal competence after palatorrhaphy (n=38); (b) speakers with velopharyngeal incompetence after palatorrhaphy (n=70), (c) adult patients with cleft palate (n=65) and (d) typical speakers (n=30). There was a highly negative correlation between VPC grade and speech intelligibility (ρ=-0.933), and a highly positive correlation between VPC and nasality (ρ=0.813). In subjective evaluation, the speech level of VPI patients was significantly lower than that of VPC patients and normal adults. Although the nasality and consonant loss rate of VPC patients were significantly higher than that of normal adults, the speech intelligibility of VPC patients was not significantly different from that of normal adults. In acoustic analysis, patients with VPI still performed poorly compared with patients with VPC. The speech function of adult cleft palate patients is affected by abnormal palatal structure and bad pronunciation habits. In subjective evaluation, there was no significant difference in speech level between VPC patients and normal adults, whereas there was significant difference between VPI patients and normal adults. The acoustic parameters were different between the 2 groups after cleft palate repair. The condition of palatopharyngeal closure after cleft palate can affect the patient's speech.

Speaking with mask in the COVID-19 era: Multiclass machine learning classification of acoustic and perceptual parameters.

The intensive use of personal protective equipment often requires increasing voice intensity, with possible development of voice disorders. This paper exploits machine learning approaches to investigate the impact of different types of masks on sustained vowels /a/, /i/, and /u/ and the sequence /a'jw/ inside a standardized sentence. Both objective acoustical parameters and subjective ratings were used for statistical analysis, multiple comparisons, and in multivariate machine learning classification experiments. Significant differences were found between mask+shield configuration and no-mask and between mask and mask+shield conditions. Power spectral density decreases with statistical significance above 1.5 kHz when wearing masks. Subjective ratings confirmed increasing discomfort from no-mask condition to protective masks and shield. Machine learning techniques proved that masks alter voice production: in a multiclass experiment, random forest (RF) models were able to distinguish amongst seven masks conditions with up to 94% validation accuracy, separating masked from unmasked conditions with up to 100% validation accuracy and detecting the shield presence with up to 86% validation accuracy. Moreover, an RF classifier allowed distinguishing male from female subject in masked conditions with 100% validation accuracy. Combining acoustic and perceptual analysis represents a robust approach to characterize masks configurations and quantify the corresponding level of discomfort.

Long-term outcomes of lateral vocal fold autologous fat injection for unilateral vocal fold paralysis

Objective: To investigate the long-term outcomes of patients with unilateral vocal fold paralysis resulting in dysphonia treated with lateral vocal fold autologous fat injection. To analyze the factors that may affect the long-term efficacy of the procedure. Methods: From July 2003 to June 2020, 163 patients (86 males and 77 females), aged 9-73 years (mean (34.50±12.94) years) with unilateral vocal fold paralysis resulting in dysphonia underwent transoral laryngoscopic injection of autologous fat into the lateral vocal folds. Subjective auditory perception assessment (GRBAS scale), objective acoustic assessment, voice handicap index (VHI) evaluation and stroboscopic laryngoscopy were compared before and after the surgery. Patients were followed up for 1 to 18 years, with median follow-up time of 6 years. SPSS 22.0 software was used for statistical analysis. Results: Of 163 patients, 17 patients (10.4%) had mild hoarseness (G1) and 146 patients (89.6%) had moderate to severe hoarseness (G2-3). Stroboscopic laryngoscopy revealed an arch-shaped vocal fold on the affected side, fixed in the paramedian position or abduction position, with obvious glottic closure fissure. Postoperatively, voice recovered to normal (G0) in 139 patients (85.3%), mild hoarseness (G1) in 18 patients (11.0%) and moderate hoarseness (G2) in 6 patients (3.7%). Of these, 131 patients (80.4%) showed significant improvement in hoarseness, 29 patients (17.8%) showed mild improvement and 3 patients (1.8%) showed no significant improvement in hoarseness. Objective acoustic parameters of Jitter, Shimmer, NHR and MPT improved significantly, as did VHI scores. Stroboscopic laryngoscopy showed medialization of the affected vocal folds, improved vocal fold closure and normal or nearly normal vocal fold mucosal waves. With a fat injection volume of 3.0-4.5 ml, the patient's subjective auditory perception scores of G, R, B and A improved more significantly within 3 months after surgery, and both VHI and MPT were significantly better since 1 year after surgery. With bilateral vocal fold injection, the B and A scores improved significantly from 1 month postoperatively compared to unilateral injections(unilateral vs. bilateral injection 1 month post-operation, tB scores=1.42,tA scores=1.51,P<0.05). Conclusions: The long-term efficacy of autologous fat injection in the paraglottic space for the treatment of unilateral vocal fold paralysis was stable. The efficacy of the surgery was related to the amount of fat injected, unilateral or bilateral of the injection.

THE ESTIMATION OF SPEECH INTELLIGIBILITY QUALITY IN ORTHODOX CHURCHES

This paper presents the estimation of speech intelligibility in unoccupied and occupied Orthodox churches "Saint George" in Žitnipotok and "Holy Great Martyr Prokopija" in Katun, Serbia, based on a comparative analysis of objective acoustic parameters: reverberation time, RT30, and speech transmission index STI,and subjective acoustic parameters: subjective intelligibility of sentences, SIsent, PB words, SIPB, and CVC logotoms, SICVC. Correlation and regression analysis confirmed a strong relationship between the analyzed acoustic parameters of speech intelligibility and reverberation time. The estimation of the quality of speech intelligibility in churches was carried out using Standard IEC 60268 - 16.

Evaluation and Improvement of Reverberation Time in the Current Enclosed Spaces with Speech Action

There are subjective and objective acoustic parameters in the creation of acoustic performance for speech action in room acoustics. Control of reverberation time affecting subjective and objective acoustic parameters is a main parameter in room acoustics. In this study, the acoustic performance assessment of the TOBB Twins Headquarters Reception Hall, which is current enclosed space with square plan and flat floor, has been performed as a case study. The evaluation focused on the relationship between reverberation time and interior surface absorption. Primarily, the reverberation time was determined according to the international standard with in-situ measurements in the current enclosed space. The reverberation time of the space was found over the reference value range. Models have been developed with the use of materials to reduce the reverberation time. In the assessment of room acoustics parameters, reverberation times of the models developed using Ecotect v.5.20 and Odeon 14.00 simulation programs have been determined. The model in which the optimum reverberation time for the speech action was obtained was constructed. After the construction, reverberation time measurements have been made again. As a result of the study, the effect of surface absorptions on the improvement of reverberation time in the enclosed spaces with square plan and flat floor for speech action has been evaluated. Suggestions have been developed to control the reflective and absorption properties of all surfaces in accordance with the evaluation and improvement of reverberation time.

Soundscape Assessment for Indoor Spaces: A case of the Higher Education Environment

As a concept, an indoor soundscape is an innovative approach to building environments with a shape that "sounds good," meeting the preferences and needs of the occupants and established according to their unique indoor soundscape perception. This paper presents the assessment of the indoor soundscape regarding objective acoustic parameters such as the equivalent noise levels (Leq) and the reverberation time (RT), and subjective method including a questionnaire survey (n = 403) in three buildings of Engineering in Al-Azhar university. The data analyses were conducted using SPSS v.21 statistical software. Overall, results show that indoor assessment is associated with five factors that are: acoustic environment factors, demographics and social factors, sound sources, duration and time of measurement, and non-acoustic parameters. The conceptual framework showed the relations between the acoustic environment, built environment, and auditory perception of university students and staff. Various buildings present a series of acoustic problems based on different activities that change the perception of users, so the outcomes feature the importance in the future considering the type of activity as a key factor in assessing the effects of noise on humans.

Study on Subjective Evaluation of Acoustic Environment in Urban Open Space Based on "Effective Characteristics".

With the continuous expansion of urban scale with dense population and traffic and the gradual improvement of residents’ requirements for environmental quality, the traditional evaluation method relying on acoustic energy is not enough to reflect the feelings of urban crowds about acoustic environment quality. The acoustic environment quality evaluation method based on human subjective perception has gradually become one of the research focuses in the field of environmental noise control. In recent years, various subjective and objective acoustic characteristic parameters have been introduced into the study of acoustic environment assessment in the global literature. However, the extraction of “effective characteristics” from a large number of physical and psychoacoustic characteristics contained in acoustic signals and the creation of a scientific and efficient subjective evaluation model have always been key technical problems in the field of acoustic environment evaluation. Based on subjective human perceptions, the overall acoustic environment quality evaluation of urban open spaces is studied in this paper. Based on the “effective characteristic” parameters and the subjective characteristic proposed in the previous research, including equivalent continuous A-weighted sound pressure level (LA), the difference between median noise and ambient background noise (L50 − L90), Sharpness (Sh), as well as satisfaction (Sat), the multivariable linear regression algorithm is used to further study the intrinsic correlation between the proposed “effective characteristics” and subjective perception. Then, a satisfaction evaluation model of the acoustic environment based on “effective characteristics” is built in this paper. Furthermore, the soundwalk evaluation experiment and the MATLAB numerical simulation experiment are carried out, which verify that the prediction accuracy of the proposed model is more than 92%, the consistency of satisfaction level is more than 88%, as well as the changes in the values of Sh and L50 − L90 have a significant impact on the satisfaction prediction of the proposed model. It shows that the proposed “effective characteristics” more comprehensively describe the quality level of the regional acoustic environment in urban open space compared with a single LA index, and the proposed acoustic environment satisfaction evaluation model based on “effective characteristics” has significant accuracy superiority and regional applicability.

Comparison and Analysis of Timbre Fusion for Chinese and Western Musical Instruments.

Timbre fusion is the theoretical basis of instrument acoustics and Chinese and Western orchestral acoustics. Currently, studies on timbre fusion are mainly focused on Western instruments, but there are some studies on the timbre fusion of Chinese instruments. In this paper, the characteristics of timbre fusion for Chinese and Western instruments are explored, focusing on the subjective attributes and objective acoustic parameters, and a series of experiments is carried out. First, a database containing 518 mixed timbre stimuli of Chinese and Western instruments was constructed to provide basic data that are necessary for the subjective and objective analyses of timbre fusion. We designed and conducted a subjective evaluation experiment of timbre perception attributes based on the method of successive categories. The experimental data were processed using statistical approaches, such as variance analysis, multidimensional preference analysis, and correlation analysis, and we studied the influence of the temporal envelopes and instrument types on fusion, segregation, roughness, and pleasantness. In addition, the differences between Chinese and Western instruments were compared based on these four perception attributes. The results show that fusion and segregation are the most important attributes for Chinese instrument timbre, while roughness is the most important attribute for Western instrument timbre. In addition, multiple linear regression, random forest, and multilayer perceptron were used to construct a set of timbre fusion models for Chinese and Western instruments. The results show that these models can better predict the timbre fusion attributes. It was also found that there are some differences between the timbre fusion models for Chinese and Western instruments, which is consistent with the analysis results of subjective experimental data. The contribution of acoustic objective parameters to the fusion model is also discussed.

Quality of Voice in Patients With Partial Deafness Before and After Cochlear Implantation

Quality of Voice in Patients With Partial Deafness Before and After Cochlear Implantation

A Preliminary Study on the Effect of Bhramari Pranayama on Voice of Prospective Singers

Bhramari Pranayama (BP) is a yogic breathing technique that involves producing a vibrating constant pitch sound emulating the buzzing of bumblebee. Since BP deals with breathing and humming in the sustained pitch, it is hypothesized that it can have implications for improving voice quality in individuals. However, there is a dearth of research available to support this assumption. Further, there are no published reports on the effect of BP on voice quality in prospective singers group. Current study was taken up to explore the effect induced by BP in the voice characteristics/quality of prospective singers. The participants included 30 healthy prospective singers in the age range of 18-35 years who were attending music schools within the state of Karnataka, India. BP regimen was demonstrated to all individuals. The voice recordings of the participants were obtained on day 0 and day 30 of BP practice. Acoustic analysis was performed to obtain AVQI and its constituent parameters and voice parameters from the MDVP program. Among the AVQI and its constituent parameters, Cepstral peak prominence-smoothed, Slope LTAS, and Tilt LTAS showed significant differences before and after BP. MDVP showed a significant difference in tremor measures before and after the practice of BP. Results of the present study indicated positive effects of BP on the voice characteristics of the prospective singers and it is reflected in objective acoustic outcome parameters of AVQI and MDVP. This supports the assumption that BP which involves yogic breathing will have beneficial effects on vocal physiology in turn leading to improved voice quality in these individuals. However, it is of future interest to validate these findings on larger samples and populations with different outcome measures. Also, future studies are warranted to verify the efficacy of BP in improving vocal quality and vocal efficiency of individuals with dysphonia.

Assessing the Soundscape Appropriateness in the Vicinity of a Heliport in an Urban Park of Quito (Ecuador) Using Immersive Audio-Visual Scenarios

Heliports are facilities that play a fundamental role in security and emergency operations. Since rotorcrafts do not need much space for take-off and landing, heliports are normally immersed in the urban fabric of our cities. However, they generate high noise levels, which can cause a nuisance, especially in outdoor areas intended for the recreation of citizens. This paper studies how helicopter noise affects the perception of the soundscape appropriateness and landscape quality in the vicinity of a heliport located in an urban park, using semantic differential scales and appraisals on the noise sources. The study area was the “Parque del Bicentenario” in Quito, Ecuador. Immersive Virtual Reality (IVR) laboratory tests using 360-degree videos and spatial audio were preferred to on-site questionnaires, given the difficulty of predicting when helicopter noise events would occur. For the statistical analysis, objective acoustic and psychoacoustic parameters have also been considered. Results show that the soundscape is perceived as more pleasant and less chaotic when there is no helicopter noise. Furthermore, with the same visual stimuli, the appraisals of the landscape are much better in the scenarios without the helicopter noise. Sharpness is the psychoacoustic parameter that best explains the variance of the subjective variables evaluated.

Investigation of a Tuff Stone Church in Cappadocia via Acoustical Reconstruction

This study investigates the indoor acoustical characteristics of a Middle Byzantine masonry church in Cappadocia. The Bell Church is in partial ruins; therefore, archival data and the church’s remains are used for its acoustical reconstruction. The study aims to formulate a methodology for a realistic simulation of the church by testing the applicability of different approaches, including field and laboratory tests. By conducting qualitative and quantitative material tests, different tuff stone samples are examined from the region. Impedance tube tests are performed on the samples from Göreme and Ürgüp to document their sound absorption performances. Previous field tests on two sites in Cappadocia are also used to compare the sound absorption performance of tuff stones, supported by acoustical simulations. The texture, physical and chemical characteristics of the stones together with the measured sound absorption coefficient values are comparatively evaluated for selecting the most suitable material to be applied in the Bell Church simulations. The church was constructed in phases and underwent architectural modifications and additions over time. The indoor acoustical environment of the church is analyzed over objective acoustical parameters of EDT, T30, C50, C80, D50, and STI for its different phases with different architectural features and functional patterns.

Subjective and Objective Evaluation of Speech in Adult Patients with Unrepaired Cleft Palate.

To explore the speech outcomes of adult patients through subjective perception evaluation and objective acoustic analysis, and to compare the differences in pronunciation characteristics between speakers with adult patients with unrepaired cleft palate and their non-cleft peers. Subjective evaluation indicators included speech intelligibility, nasality, and consonant missing rate, whereas objective acoustic parameters included normalized vowel formants, voice onset time, and the analysis of three-dimensional spectrogram and spectrum, were carried out on speech samples produced by 2 groups of speakers: (a) speakers with unrepaired cleft palate ( n = 65, mean age = 25.1 years) and (b) typical speakers ( n = 30, mean age = 23.7 years). Compared with typical speakers, individuals with unrepaired cleft palate exhibited a lower speech intelligibility with higher nasality and consonant missing rate, the missing rate is highest for the 6 consonants syllables The acoustic parameters are mainly manifested as differences in vowel formants and voice onset time. The results revealed important acoustical differences between adult patients with unrepaired cleft palate and typical speakers. The trend of spectral deviation may have contributed to the difficulty in producing pressure vowels and aspirated consonants in individuals with speech disorders related to cleft palate.

Functional results of endoscopic arytenoid abduction lateropexy for bilateral vocal fold palsy

PurposeEndoscopic arytenoid abduction lateropexy (EAAL) is a reliable surgical solution for the minimally invasive treatment of bilateral vocal fold palsy (BVFP), providing a stable airway by the lateralization of the arytenoid cartilages with a simple suture. The nondestructive manner of the intervention theoretically leads to higher regeneration potential, thus better voice quality. The study aimed to investigate the respiratory and phonatory outcomes of this treatment concept.Methods61 BVFP patients with significant dyspnea associated with thyroid/parathyroid surgery were treated by unilateral EAAL. Jitter, Shimmer, Harmonics to Noise Ratio, Maximum Phonation Time, Fundamental frequency, Voice Handicap Index, Dysphonia Severity Index, Friedrich’s Dysphonia Index, Global-Roughness-Breathiness scale, Quality of Life, and Peak Inspiratory Flow were evaluated 18 months after EAAL.ResultsAll patients had a stable and adequate airway during the follow-up. Ten patients (16.4%) experienced complete bilateral motion recovery with objective acoustic parameters in the physiological ranges. Most functional results of the 13 patients (21.3%) with unilateral recovery also reached the normal values. Fifteen patients (24.6%) had unilateral adduction recovery only, with slightly impaired voice quality. Eleven patients (18.0%) had false vocal fold phonation with socially acceptable voice. In 12 patients (19.7%) no significant motion recovery was detected on the glottic level.ConclusionEAAL does not interfere with the potential regeneration process and meets the most important phoniatric requirements while guaranteeing the reversibility of the procedure—therefore serving patients with transient palsy. Further, a socially acceptable voice quality and an adequate airway are ensured even in cases of permanent bilateral vocal fold paralysis.

The effects of different ceiling structures and plan typologies on acoustical conditions of historical mosques

Mosque is a building type used by Muslim people consists of speech and music rituals. Good acoustical condition in mosques is an important issue to provide desired acoustical environment for prayers and Imams during different worship rituals. Prayers need to feel individuality in praying and the sense of unity in recitation of the Quran, hymns. Worship activities need a high level of speech intelligibility and to satisfy prayers in the spiritual aspects which make people feel closed to the God. In the context of study, six historical mosques in Turkey, with different types of cover structures and plan typologies, are designated as study areas. The present study contains two methods which the first one is collecting acoustical data by measurements and the second consists of mathematical modelling software program. The purpose of study to investigate effects of different plan typology and ceiling structures on acoustical characteristics in mosques with similar volume. Also, distribution of acoustical parameters and the suitability of the values obtained through acoustic simulations and measurements to the recommended values are aimed to be investigated. As a result of the investigations, it was concluded that the objective acoustic parameters of mosques changed according to the geometric parameter properties.

Can preoperative results predict the need for future reintervention following injection laryngoplasty for unilateral vocal fold paralysis?

PurposeThe objective was to investigate whether a patient’s preoperative test results can predict the need for future reoperation in unilateral vocal fold paralysis (UVFP).MethodsA single-centre retrospective study was performed. The study group consisted of 18 patients with UVFP who had been treated with injection laryngoplasty but who required further treatment and were augmentated again within 36 months. The control group consisted of 33 injected patients who had not required reintervention up to 36 months later.ResultsOnly glottal gap was associated with a relative risk for reinjection. Glottal gap was found to be severe in 77.8% of the patients from the study group compared to 42.4% of the controls, and the difference was statistically significant. The kind of injected material (calcium hydroxylapatite or hyaluronic acid), age, and voice assessment (perceptual, objective, or subjective) did not seem to affect the likelihood of reoperation being needed. There were no between-group statistically significant differences in individual aspects of the GRBAS scale. The global score was slightly higher in the study group, but it did not reach statistical significance (U = 198.5; p = 0.09). A comparison of VHI scores did not yield statistically significant differences between the study and control groups. No significant differences in objective acoustic voice parameters were observed between the groups.ConclusionOnly glottal gap occurred to be associated with a relative risk for reinjection. A kind of injected material (CaHA or HA), age, perceptual, objective and subjective voice assessment do not seem to impact the likelihood of reoperation in patients with UVFP.