Persona: Filipa M.B., Lã
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Filipa M.B., Lã
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Publicación Professional male singers’ formant strategies for the vowel /a/(Taylor & Francis, 2011-11-15) Sundberg, Johan; Filipa M.B., Lã; Gill, Brian P.; Filipa M.B., LãCertain spectrum characteristics have been identified as important for register equalization around the male passaggio, an effect ascribed to formant tuning although descriptions of formant tuning diverge. Eight professional singers sang scales including their passaggio range on different vowels, applying two formant tuning strategies as found in (Citation) classical and (Citation) non-classical singing. Formant frequencies were measured using inverse filtering. Results revealed differences between the two strategies. For the classical formant tuning, systematic changes of formant frequencies with pitch were observed. For the highest note sung on /a/, was below the second partial and in the vicinity of the third. Similar spectrum characteristics were achieved by different and values between singers.Publicación Glottal airflow and glottal area waveform characteristics of flow phonation in untrained vocally healthy adults(Elsevier, 2022-01) Patel, Rita R.; Sundberg, Johan; Gill, Brian P.; Filipa M.B., Lã; Filipa M.B., LãObjective To examine flow phonation characteristics with regard to vocal fold vibration and voice source properties in vocally healthy adults using multimodality voice measurements across various phonation types (breathy, neutral, flow, and pressed) and loudness conditions (typical, loud, and soft). Participants and Methods Vocal fold vibration, airflow, acoustic, and subglottal pressure was analyzed in 13 untrained voices (six female and seven male). Participants repeated the syllable / pæ:/ using breathy, neutral, flow, and pressed phonation during typical, loud, and soft loudness conditions. Glottal area (GA) waveforms were extracted from high-speed videoendoscopy; glottal flow was derived from inverse filtering the airflow or the audio signal; and subglottal pressure was measured as the intraoral pressure during /p/ occlusion. Results Changes in phonation type and loudness conditions resulted in systematic variations across the relative peak closing velocity derived from the GA waveform for both males and females. Amplitude quotient derived from the flow glottogram varied across phonation types for males. Conclusion Multimodality evaluation using the GA waveform and the inverse filtered waveforms revealed a complex pattern that varied as a function of phonation types and loudness conditions across males and females. Emerging findings from this study suggests that future large-scale studies should focus on spatial and temporal features of closing speed and closing duration for differentiating flow phonation from other phonation types in untrained adults with and without voice disorders.Publicación Intonation and Expressivity: A Single Case Study of Classical Western Singing(Elsevier, 2013-05) Sundberg, Johan; Himonides, Evangelos; Filipa M.B., LãPrevious studies have shown that singers tend to sharpen phrase-peak tones as compared with equally tempered tuning (ETT). Here we test the hypothesis that this can serve the purpose of musical expressivity. Data were drawn from earlier recordings, where a professional baritone sang excerpts as void of musical expression as he could (Neutral) and as expressive as in a concert (Concert). Fundamental frequency averaged over tones was examined and compared with ETT. Phrase-peak tones were sharper in excited examples, particularly in the Concert versions. These tones were flattened to ETT using the Melodyne software. The manipulated and original versions were presented pairwise to a musician panel that was asked to choose the more expressive version. By and large, the original versions were perceived as more expressive, thus supporting the common claim that intonation is a means for adding expressivity to a performance.Publicación Effects of the menstrual cycle and the oral contraception on singer´s pitch control(American Speech-Language-Hearing Association (ASHA), 2012-02-01) Filipa M.B., Lã; Sundberg, Johan; Howard, David M.; Sa Couto, Pedro; Freitas, Adelaide; Filipa M.B., LãPurpose: Difficulties with intonation and vibrato control during the menstrual cycle have been reported by singers; however, this phenomenon has not yet been systematically investigated. Method: A double-blind randomized placebo-controlled trial assessing effects of the menstrual cycle and use of a combined oral contraceptive pill (OCP) on pitch control in singing is presented. Audio-electrolaryngograph recordings were made and blood samples were taken from 9 singers in each of the 3 phases of the menstrual cycle both under the placebo and the OCP conditions for a total of 6 months. Participants sang an exercise consisting of an ascending octave followed by a descending major triad, starting on pitches F4 and B4. Pitch control was assessed in terms of the octave's deviations from pure intonation and of the vibrato rate and extent. Results: Significant differences were found between the 3 phases of the cycle regarding octave size only for pitch F5 during OCP use. Significant vibrato rate differences between placebo and OCP conditions were found only for pitch F5. Conclusion: OCP use may have an effect on pitch control in singers. Possible explanations point to a complex interaction between hormonal milieu and pitch control, enhancing the need for longitudinal studies.Publicación Avaliação aerodinâmica e acústica da fonte de voz(Thieme Revinter, 2022) Sundberg, Johan; Filipa M.B., Lã; Filipa M.B., LãPublicación Soul and Musical Theatre. A comparison of two vocal styles(Elsevier, 2017-03-01) Hallqvist, Hanna; Filipa M.B., Lã; Sundberg, Johan; Filipa M.B., LãThe phonatory and resonatory characteristics of nonclassical styles of singing have been rarely analyzed in voice research. Six professional singers volunteered to sing excerpts from two songs pertaining to the musical theater and to the soul styles of singing. Voice source parameters and formant frequencies were analyzed by inverse filtering tones, sung at the same fundamental frequencies in both excerpts. As compared with musical theater, the soul style was characterized by significantly higher subglottal pressure and maximum flow declination rate. Yet sound pressure level was lower, suggesting higher glottal resistance. The differences would be the effects of firmer glottal adduction and a greater frequency separation between the first formant and its closest spectrum partial in soul than in musical theater.Publicación Fundamental frequency disturbances in female and male singers' pitch glides through long tube with varied resistances(Acoustical Society of America (ASA), 2023-08-09) Sundberg, Johan; Granqvist, Svante; Filipa M.B., LãSource-filter interaction can disturb vocal fold vibration frequency. Resonance frequency/bandwidth ratios (Q-values) may affect such interaction. Occurrences of fundamental frequency (fo) disturbances were measured in ascending pitch glides produced by four female and five male singers phonating into a 70 cm long tube. Pitch glides were produced with varied resonance Q-values of the vocal tract + tube compound (VT + tube): (i) tube end open, (ii) tube end open with nasalization, and (iii) with a piece of cotton wool in the tube end (conditions Op, Ns, and Ct, respectively). Disturbances of fo were identified by calculating the derivative of the low-pass filtered fo curve. Resonance frequencies of the compound VT+tube system were determined from ringings and glottal aspiration noise observed in narrowband spectrograms. Disturbances of fo tended to occur when a partial was close to a resonance of the compound VT+tube system. The number of such disturbances was significantly lower when the resonance Q-values were reduced (conditions Ns and Ct), particularly for the males. In some participants, resonance Q-values seemed less influential, suggesting little effect of source-filter interaction. The study sheds light on factors affecting source-filter interaction and fo control and is, therefore, relevant to voice pedagogy and theory of voice production.Publicación Augmented visual-feedback of airflow: Immediate effects on voice-source characteristics of students of singing(['SAGE', 'SEMPRE'], 2021-07-12) Filipa M.B., Lã; Sundberg, Johan; Granqvist, Svante; Filipa M.B., LãGlottal adduction is a crucial aspect in voice education and vocal performance: it has major effects on phonatory airflow and, consequently, on voice timbre. As the voice is a non-visible musical instrument, controlling it could be facilitated by providing real-time visual feedback of phonatory airflow. Here, we test the usefulness of a flow ball (FB) training device, visualizing, in terms of the height of a polystyrene ball placed in a plastic basket, phonatory airflow during phonation. Audio and electroglottographic recordings of five postgraduate, classically trained singer students were made under three subsequent conditions: before, during, and after phonating into the FB. The calibrated audio signal was inverse-filtered, using an electroglottograph signal to guide the manual tuning of the inverse filters. Mean phonatory airflow, peak-to-peak pulse amplitude, and normalized amplitude quotient were extracted from the resulting flow glottograms. After the FB condition, increases of mean flow and peak-to-peak pulse amplitude were observed in four singers. In addition, the singers’ mean normalized amplitude quotient increased significantly. The findings, although exploratory, suggest that reduction of glottal adduction.Publicación Voice source variation between vowels in male opera singers(Elsevier, 2016-09-01) Sundberg, Johan; Filipa M.B., Lã; Gill, Brian P.; Filipa M.B., LãObjectives: The theory of non-linear source-filter interaction predicts that the glottal voice source should be affected by the frequency relationship between formants and partials. An attempt to experimentally verify this theory is presented. Study design: Glottal voice source and electrolaryngograph (ELG) signal differences between vowels were analyzed in vowel sequences, sung at four pitches with the same degree of vocal loudness by professional opera singers. Also, the relationships between such differences and the frequency distance between the first formant (F1) and its closest partial were examined. Methods: A digital Laryngograph microprocessor was used to simultaneously record audio and ELG signals. The former was inverse-filtered and voice source parameters and formant frequencies were extracted. The amplitude quotient of the derivative of the ELG signal (AQdELG) and the contact quotient were also compared. Results: A one-way repeated measures ANOVA revealed significant differences between vowels, for contact quotient at four pitches and for MFDR at three pitches. For other voice source parameters, differences were found at one or two pitches only. No consistent correlation was found between MFDR and the distance between F1 and its closest partial. Conclusions: The glottal voice source tends to vary between vowels, presumably because of non-linear source-filter interaction, but the variation does not seem to be dependent upon the frequency distance between F1 and its closest partialPublicación Contact quotient versus closed quotient: a comparative study on professional male singers(Elsevier, 2015-03) Filipa M.B., Lã; Sundberg, Johan; Filipa M.B., LãObjectives: The term “closed quotient” is frequently used for data derived both from inverse filtering and from electroglottography. In the former case it is defined as the ratio between the closed phase and the period, as measured in flow glottograms (FLOGG), while in the latter case it is defined as the time interval between the falling and rising parts of the electroglottogram (EGG), measured at some percentage of the peak-to-peak amplitude. The study aims at analyzing differences between EGG and FLOGG based closed quotients and their relationships with voice source parameters. Study Design: Comparative study Methods: FLOGG based and EGG based measures collected from five professional male singers were compared, under different pitch and loudness conditions. Results: As compared with the FLOGG based quotient, the EGG based quotient (i) varied more between subjects, (ii) presented greater values, (iii) varied less with subglottal pressure, (iv) varied less with the normalized amplitude quotient (i.e. the ratio between the flow pulse amplitude and the product of period and maximum flow declination rate), and (v) varied less with the relative amplitude of the voice source fundamental. Conclusions: Although positively related, FLOGG based and EGG based closed quotients differ and must not be confused.