Vowel Intelligibility in Classical Singing

Vowel intelligibility during singing is an important aspect of communication during performance. The intelligibility of isolated vowels sung by Western classically trained singers has been found to be relatively low, in fact, decreasing as pitch rises, and it is lower for women than for men. The lack of contextual cues significantly deteriorates vowel intelligibility. It was postulated in this study that the reduced intelligibility of isolated sung vowels may be partly from the vowels used by the singers in their daily vocalises. More specifically, if classically trained singers sang only a few American English vowels during their vocalises, their intelligibility for American English vowels would be less than for those classically trained singers who usually vocalize on most American English vowels. In this study, there were 21 subjects (15 women, 6 men), all Western classically trained performers as well as teachers of classical singing. They sang 11 words containing 11 different American English vowels, singing on two pitches a musical fifth apart. Subjects were divided into two groups, those who normally vocalize on 4, 5, or 6 vowels, and those who sing all 11 vowels during their daily vocalises. The sung words were cropped to isolate the vowels, and listening tapes were created. Two listening groups, four singing teachers and five speech-language pathologists, were asked to identify the vowels intended by the singers. Results suggest that singing fewer vowels during daily vocalises does not decrease intelligibility compared with singing the 11 American English vowels. Also, in general, vowel intelligibility was lower with the higher pitch, and vowels sung by the women were less intelligible than those sung by the men. Identification accuracy was about the same for the singing teacher listeners and the speech-language pathologist listeners except for the lower pitch, where the singing teachers were more accurate.     

Heartbeat-related fundamental frequency and amplitude variation in healthy young and elderly male voices

Modulation of the acoustic amplitude and fundamental frequency of a sustained vowel across the heart cycle was examined via signal-averaging. Ten normal young and ten normal elderly men prolonged phonations of the vowel /a/. Consistent with previous studies, the young men's maximal heart-beat-related frequency and amplitude variations averaged 1.0% and 8.4% of their respective means. Such modulation was estimated to account for 6.6% of the absolute jitter and 11.3% of the shimmer measured in these voice samples. The extent of this systematic variation was significantly greater in the older voices, averaging 2.4% of the mean frequency and 15.4% of the mean amplitude and was estimated to account for approximately 12.9% and 15.8% of their mean absolute jitter and shimmer, respectively. This age-related difference is thought to be a manifestation of involutional changes in laryngeal vascular and soft tissues and in ventilatory biomechanics.     

The speaker''s formant in male voices

Spectral analysis of vowels during connected speech can be performed using the spectral intensity distribution within critical bands corresponding to a natural scale on the basilar membrane. Normalization of the spectra provides the opportunity to make objective comparisons independent from the recording level. An increasing envelope peak between 3,150 and 3,700 Hz has been confirmed statistically for a combination of seven vowels in three groups of male speakers with hoarse, normal, and professional voices. Each vowel is also analyzed individually. The local energy maximum is called “the speaker's formant” and can be found in the region of the fourth formant. The steepness of the spectral slope (i.e. the rate of decline) becomes less pronounced when the sonority or the intensity of the voice increases. The speaker's formant is connected with the sonorous quality of the voice. It increases gradually and is approximately 10 dB higher in professional male voices than in normal male voices at neutral loudness (60 dB at 0.3 min). The peak intensity becomes stronger (30 dB above normal voices) when the overall speaking loudness is increased to 80 dB. Shouting increases the spectral energy of the adjacent critical bands but not the speaker's formant itself.     

Study on some aspects of the “singer's formant” in north indian classical singing

This article deals with a spectrographic analysis of the singer's formant as occurred during singing of the vowels /a/, /i/, and /o/ in North Indian classical vocal music. The resonance balance, center frequency, and band-width are shown as a function of fundamental frequency for eight singers.Two new parameters have been defined viz. asymmetry parameter (A) and spectral energy balance (W). Their variation with fundamental frequency is shown.     

Behavior of laryngeal muscles of the late William Vennard

Behavior of the cricothyroid, lateral cricoarytenoid, vocalis, and interarytenoid muscles of William D. Vennard was electromyographically investigated. This article demonstrates electromyographic recordings that have not been published. Data presentation and discussion are focused on vocal registers, some phrases for voice training and warm-up, vowels, phonation modes, fundamental frequency control, the interarytenoid muscle, and some nonsinging behaviors