Effects of Therapy With Semi-occluded Vocal Tract and Choir Training on Voice in Adult Individuals With Congenital, Isolated, Untreated Growth Hormone Deficiency

Objectives: Voice is produced by the vibration of the vocal folds expressed by its fundamental frequency (Hz), whereas the formants (F) are fundamental frequency multiples, indicating amplification zones of the vowels in the vocal tract. We have shown that lifetime isolated growth hormone deficiency (IGHD) causes high pitch voice, with higher values of most formant frequencies, maintaining a prepuberal acoustic prediction. The objectives of this work were to verify the effects of the therapy with a semi-occluded vocal tract (SOVTT) and choir training on voice in these subjects with IGHD. We speculated that acoustic vocal parameters can be improved by SOVTT or choir training. Study Design: This is a prospective longitudinal study without control group. Methods: Acoustic analysis of isolated vowels was performed in 17 adults with IGHD before and after SOVTT (pre-SOVTT and post-SOVTT) and after choir training (post training), in a 30-day period. Results: The first formant was higher in post training compared with the pre-SOVTT (P = 0.009). The second formant was higher in post-SOVTT than in pre-SOVTT (P = 0.045). There was a trend of reduction in shimmer in post-choir training in comparison with pre-SOVTT (P = 0.051), and a reduction in post-choir training in comparison with post-SOVTT (P = 0.047). Conclusions: SOVTT was relevant to the second formant, whereas choir training improved first formant and shimmer. Therefore, this speech therapy approach was able to improve acoustic parameters of the voice of individuals with congenital, untreated IGHD. This seems particularly important in a scenario in which few patients are submitted to growth hormone replacement therapy.