Methodological Approaches for Vocal Folds Experiments in Laryngology: A Scoping Review.

OBJECTIVE: The aim of this study was to describe the methodological approaches adopted in experimental researches in laryngology intervention studies. METHODS: The study was performed as a scoping review using the electronic databases Medline (PubMed), Web of Science, Embase, BioMed Central and SCOPUS. These databases were manually searched from 1995 (or its inception) until the most recently published articles in June 2022. The inclusion criteria were as follows: a) studies performed with animal models in voice and/or larynx therapy, intervention and/or surgery; b) studies with participant populations composed with animals; c) studies containing original research; d) studies performed with at least one objective measurement for treatment and or intervention; e) studies reporting at least one method of larynx intervention; and f) publications written in English, Spanish or Portuguese. The exclusion criteria were as follows: a) studies considering without any objective intervention and or treatment; b) studies without animal models; and c) studies that reviewed articles or books. These criteria were set to increase inter-study comparability. RESULTS: There were found 26 studies that showed that in experimental laryngology. There were retrieved four main characteristics in the retrieved studies. It was observed five major groups of experimental models used for assessing vocal folds: dog (38.5%), rat/mouse (23,1%), pig (23.1%), rabbit (19.2%), human (11.5%), and sheep (3.8%). In addition, three characteristics were observed: sample (up to 20 subjects 88.5%), type of surgery/intervention (100%) and duration (up to 30 days 61.5%). CONCLUSION: In experimental laryngology, the state of the art is grounded on mainly in dog, rat and pig in vocal folds assessment. Up to 20 subjects, surgery/intervention and experimental trial lasting no more than 30 days are frequent methodological approaches in this research field.

Effect of the Finnish Tube on the Voice of a Deaf Musician: A Case Report.

PURPOSE: To verify the auditory-perceptual and acoustic effects of the semioccluded vocal tract exercise with Finnish tube on the vocal quality of a deaf musician. METHODS: A seven-day protocol with Finnish tube was performed with guidance for its home replication twice a day. A 46-years-old man with profound bilateral sensorineural hearing loss, musician and composer participated. Before and after the application of the protocol had undergone tonal audiometry, nasofibrolaryngoscopy, acoustic analysis with Praat and auditory-perceptual evaluation of the voice with Voice Profile Analysis Scheme for Brazilian Portuguese. RESULTS: The postintervention auditory-perceptual analysis identified reduction of the deviation in lip spreading, extensive labial range, raised tongue body, pharyngeal expansion, nasal resonance, larynx height, larynx and vocal tract tension and irregularity, pitch, speech rate, and a better respiratory support. The maximum phonation time reduced, probably because of elimination of the abrupt vocal attack and tension, articulatory deviations, improvement in voicing and the absence of the use of expiratory reserve air. The fundamental frequency became lower, and the first, second, third, and fourth formants became higher. The jitter increased, and the shimmer reduced. CONCLUSION: The use of the Finnish tube might have facilitated the voicing sensations in the deaf musician, by enhancing the tactile-kinesthetic perception of the vocal tract and brought a greater source-filter interaction.

Auditory-Perceptual Evaluation of Voice Quality of Cochlear-implanted and Normal-hearing Individuals: A Reliability Study.

OBJECTIVE: This study aimed to present an experience in rating voices of adults with normal hearing and adults with cochlear implants and critically examine the outcomes, discussing pros and cons of the methodology used. STUDY DESIGN: This is a cross-sectional, prospective study. METHODS: One hundred and fifty voice samples, consisting of 50 sustained vowels, 50 samples of connected speech, and 50 samples of conversational speech, belonging to 25 adults with hearing impairment with cochlear implants and 25 adults with normal hearing, were perceptually analyzed for inter-rater agreement and intra-rater reliability. Three experienced judges rated the voice samples using visual analog scales of parameters considered relevant for cochlear-implanted population such as articulation, intonation, and resonance. The raters participated in three training sessions for calibration and had 1 month to complete the ratings individually. Twenty percent of the samples were repeated randomly to verify intra-rater reliability. The levels of agreement and reliability were verified using the interclass correlation coefficient. RESULTS: The inter-rater agreement varied widely across the parameters and speech tasks, from poor to excellent agreement. The only parameter for which the raters maintained consistently good or excellent agreement for all groups and emissions was the pitch. For intra-rater reliability, two of the raters presented excellent reliability for most parameters across all of the speech tasks, whereas one rater presented more inconsistencies. CONCLUSIONS: In this reliability study, factors such as extensive deadline for the auditory perceptual evaluation, lack of periodic recalibration, speech tasks, and familiarity with the population studied were identified as factors that contributed to inconsistent reliability results.