Acoustic and perceptual voice parameters in subclinical and overt primary hypothyroidism

Voice changes in reproductive disorders, thyroid disorders and diabetes: a review

“…What is interesting is the studies conducted by Birkent et al and Junuzović-Žunić et al ( 33 , 34 ) also compared acoustic parameters in the hypo- and euthyroid group, with the difference that the study and control group concerned the same patients before and after the proper treatment. The common finding in studies carried out by Mohammadzaneh et al , Ersoz Unlu et al and Birkent et al ( 31 , 32 , 33 ) was significantly lower fundamental frequency in a state of hypothyroidism. This important result can be explained by the decreased number of vocal fold vibrations in a time unit due to the vocal fold oedema and muscle weakness, which occur typically in a state of insufficient thyroid hormones secretion.…”

“…In another research paper, Ersoz Unlu et al ( 32 ) analysed the vocal differences between a group of 26 females affected by overt hypothyroidism, 26 females with subclinical hypothyroidism and a group of healthy individuals. In this research, the assessed parameters included the voice self-assessment by VHI-10 questionnaire, the perceptual evaluation with the use of GRBAS scale and the acoustic variables.…”

“…F0, voice turbulence index, higher peak to peak amplitude variation, shimmer, noise-to-harmonic ratio, soft phonation index, amplitude tremor intensity; Only females ( vs control group) : lower max. F0 higher the standard derivation of fundamental frequency, fundamental frequency variation Not applicable Self-assessment of pharyngolaryngeal symptoms Dryness in larynx and pharynx, dyspnea, sensation of lump in the throat, globus, oropharyngeal dysphagia, vague pain, itching, burn in the larynx Both genders: 53.3%: dryness in the larynx or pharynx 49.2%: dyspnea 43.3%: sensation of a lump in throat Ersoz Unlu et al ( 32 ) 26 females with primary overt hypothyroidism Not applicable Self-assessment of vocal symptoms Voice Handicap Index-10 Overt hypothyroid patients ( vs control group) : higher VHI-10; Subclinical hypothyroid patients ( vs control group) : no differences 26 females with subclinical hypothyroidism The standardized text read by the participants Perceptual evaluation GRBAS scale Overt hypothyroid patients ( vs control group) : no differences; Subclinical hypothyroid patients ( vs control group) : no differences The vowel ‘a’ sustained for 3 s Acoustic parameters Mean, highest and lowest fundamental frequencies, jitter, shimmer, noise-to-harmonics ratio Overt hypothyroid patients ( vs control group) : lower mean, highest and lowest fundamental frequency;Subclinical hypothyroid patients ( vs control group) : no differences Birkent et al ( 33 ) 24 females with thyroidectomy-related hypothyroidism: pre- and post-treatment period assessment The vowel ‘a’ sustained for 3 s …”

“…Mohammadzadeh et al ( 31 ) were the only ones who conducted the research that compared acoustic parameters between hypothyroid and euthyroid individuals, stratifying both groups by gender. On the other hand, the research conducted by Ersoz Unlu et al ( 32 ) compared the healthy participants not only to the group of overtly hypothyroid but also subclinically hypothyroid females. What is interesting is the studies conducted by Birkent et al and Junuzović-Žunić et al ( 33 , 34 ) also compared acoustic parameters in the hypo- and euthyroid group, with the difference that the study and control group concerned the same patients before and after the proper treatment.…”

“…In terms of perceptual evaluation, in the research conducted by Mohammadzaneh et al ( 31 ), the participant’s speech disorders were assessed with no standardized questionnaire, which enables comparing this analysis to the results obtained by Junuzović-Žunić et al ( 34 ) and Ersoz Unlu et al ( 32 ), where the GRBAS scale was used. However, the results of those two latter studies also differ from each other, since Ersoz Unlu et al ( 32 ) did not describe any differences between the two study groups and the healthy individuals and Junuzović-Žunić et al ( 34 ) found some changes in the perceptual evaluation of hypothyroid patients’ voice. Unfortunately, the study by Junuzović-Žunić et al ( 34 ) does not demonstrate the detailed statistical analysis of the data devoted to perceptual evaluation, describing the trend of each parameter with the word ‘different’ instead of explaining whether the discussed perceptual feature decreased or increased.…”