Lip trill effects on vocal function, vocal pitch, and harmonics-to-noise ratio: A multiple baseline study of three vocally healthy females

Background@#The lip trill is a semi-occluded vocal tract exercise found to have positive outcomes on vocal parameters of healthy individuals after a single session. However, the effect of several lip trill sessions has not been studied.@*Objective@#This study investigated the effect of a 3- to 4-week lip trill exercise program on Maximum Phonation Time (MPT), Maximum Phonation Frequency Range (MPFR), Harmonics-to-Noise Ratio (HNR), and mean Speaking Fundamental Frequency (mean SFF).@*Methods@#Three vocally untrained healthy females with perceptually normal voices participated in a multiple-baseline, single-case experimental research. Five to seven direct training sessions were randomly assigned. Self-implementation was encouraged thereafter. Participants were assessed on all outcome measures for 15 sessions. Data were visualized and inspected. Cohen’s d was also derived using Standardized Mean Difference for single-subject research.@*Results@#Visual and statistical analyses revealed a decreased MPT when training was introduced, increased MPFR variability during the training phase, and increased stability in mean SFF post-training. Perceived effects include vocal freedom, decreased laryngeal stress, and vocal conditioning. Vocal outcomes in one participant yielded a significant effect on MPFR and mean SFF and a small effect on HNR.@*Conclusion@#There is evidence of lip trill effect on pitch control and vocal conditioning. Findings also revealed that motivation, exercise frequency, and adherence could contribute to positive gains in vocally healthy speakers. Further investigation in consideration of the study findings and limitations is warranted.

Normatização de medidas acústicas para vozes normais / Standardization of acoustic measures for normal voice patterns

Pesquisas têm estabelecido que cada serviço deve estabelecer seus padrões normativos para a análise acústica. O objetivo do presente estudo é normatizar as medidas de freqüência fundamental (fo), jitter, shimmer e proporção harmônico-ruído (PHR) para adultos jovens com voz normal. MÉTODO: Participaram deste estudo 20 homens e 20 mulheres, de 20 a 45 anos de idade, sem sinais e sintomas de problemas vocais, produzindo as vogais sustentadas /a/ e /é/, analisadas pelo programa CSL- 4300 Kay-Elemetrics. RESULTADOS: Para as mulheres, respectivamente para a vogal /a/ e /é/ os valores médios foram: fo de 205,82Hz e 206,56Hz; jitter de 0,62 por cento e 0,59 por cento; shimmer de 0,22dB e 0,19dB; PHR de 10,9 dB e 11,04 dB. Para os homens, respectivamente para a vogal /a/ e /é/, os valores médios foram: fo de 119,84Hz e 118,92Hz; jitter de 0,49 por cento e 0,5 por cento; shimmer de 0,22 dB e 0,21 dB; PHR de 9,56 dB e 9,63dB. As medidas de fo e PHR foram significativamente maiores para as mulheres em comparação aos homens. CONCLUSÃO: As diferenças entre os nossos resultados e os dos outros autores confirmam a necessidade de se realizar a normatização para cada programa a ser utilizado.

Studies have established that normative data is necessary for acoustic analysis. The aim of the present study is to standardize fundamental frequency measures (fo), jitter, shimmer and harmonic-noise ratio (HNR) for young adults with normal voice. METHOD: 20 males and 20 females, between 20 and 45 years, without signs and symptoms of vocal problems; CSL-4300 Kay-Elemetrics; vowels /a/ and /é/. RESULTS: for females, vowels /a/ and /é/ had average measures of: fo 205.82 Hz and 206.56 Hz; jitter of 0.62 percent and 0.59 percent; shimmer of 0.22 dB and 0.19 dB; PHR of 10.9 dB and 11.04 dB, respectively. For males, vowel /a/ and /é/ had average measures of: fo 119.84 Hz and 118.92 Hz; jitter of 0.49 percent and 0.5 percent; shimmer of 0.22 dB and 0.21 dB; HNR 9.56 dB and 9.63 dB, respectively. Both fo and NHR female measures were significantly higher than their male counterparts. CONCLUSION: our results differ from the literature; therefore, it is important to standardize the program in use.