Accurate measurement of the softest sound levels of phonation presents technical and methodological challenges. This study aimed at (1) reliably obtaining normative data on sustained softest sound levels for the vowel [a:] at comfortable pitch; (2) comparing the results for different frequency and time weighting methods; and (3) refining the Union of European Phoniatricians' recommendation on allowed background noise levels for scientific and equipment manufacturers' purposes. Eighty healthy untrained participants (40 females, 40 males) were investigated in quiet rooms using a head-mounted microphone and a sound level meter at 30 cm distance. The one-second-equivalent sound levels were more stable and more representative for evaluating the softest sustained phonations than the fast-time-weighted levels. At 30 cm, these levels were in the range of 48-61 dB(C)/41-53 dB(A) for females and 49 - 64 dB(C)/35-53 dB(A) for males (5% to 95% quantile range). These ranges may serve as reference data in evaluating vocal normality. In order to reach a signal-to-noise ratio of at least 10 dB for more than 95% of the normal population, the background noise should be below 25 dB(A) and 38 dB(C), respectively, for the softest phonation measurements at 30 cm distance. For the A-weighting, this is 15 dB lower than the previously recommended value.
- MeSH
- akustika přístrojové vybavení MeSH
- časové faktory MeSH
- dospělí MeSH
- fonace fyziologie MeSH
- hluk MeSH
- kalibrace MeSH
- kvalita hlasu MeSH
- lidé středního věku MeSH
- lidé MeSH
- měniče MeSH
- mladiství MeSH
- mladý dospělý MeSH
- počítačové zpracování signálu MeSH
- poměr signál - šum MeSH
- referenční hodnoty MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The knowledge of the dynamic extremes of human voice is important for voice diagnostics and for scientific purposes. Numerous authors have published on the dynamic range of human voice but the methodology has been quite heterogenous and the exact values of the dynamic extremes are often unclear. There has been a need for a carefully documented study about measuring extreme limits of normal voice with easily reproducible methodology. We measured 37 subjects, 23 women and 14 men for this experiment. Two microphones were used (one head-mounted and one stand-mounted), which were calibrated at a standard distance 30 cm from the mouth. The head-mounted microphone was used for measuring the softest phonations and the stand-mounted for measuring the loudest ones. The loudest level was determined from calling the Czech words “Hej, Hou, Haló” as the peak sound level. The softest level was determined as a minimum of the fast time-weighted sound level from the softest sustained phonations on vowel [a:]. The standard weighting filtres A, C or Z and a custom high-pass filter were used to decrease ambient noise. The level of the loudest phonation was found to be 127 dB at 30 cm from the mouth (male subject) and the softest phonation was found to be 31 dB (A-weighted) at 30 cm from mouth (male subject). These levels appear to be greater than those measured previously and can serve as a basis for specifying dynamic ranges of microphone intended for voice measurements.
- MeSH
- akustika řeči MeSH
- audiovizuální pomůcky využití MeSH
- experimenty na lidech MeSH
- financování organizované MeSH
- fonace fyziologie MeSH
- fonetika MeSH
- hlas fyziologie MeSH
- kalibrace MeSH
- kvalita hlasu fyziologie MeSH
- lidé MeSH
- percepce řeči MeSH
- počítačové zpracování signálu přístrojové vybavení MeSH
- statistika jako téma MeSH
- vlnková analýza MeSH
- vnímání výšky zvuku MeSH
- Check Tag
- lidé MeSH
