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Filipa M.B., Lã

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Filipa M.B., Lã
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Mostrando 1 - 10 de 34
  • Publicación
    Formant Tuning Strategies in Professional Male Opera Singers
    (Elsevier, 2013-05) Sundberg, Johan; Filipa M.B., Lã; Gill, Brian P.; Filipa M.B., Lã
    The term “formant tuning” is generally used for the case that one of the lowest formant frequencies coincides with the frequency of a source spectrum partial. Some authors claim that such coincidence is favorable and belongs to the goals of classical opera voice training, whereas other authors have found evidence for advising against it. This investigation analyzes the relationships between formant frequencies and partials in professional singers, who sang scales on the vowels /a/, /u/, /i/, and /ae/ in a pitch range including the passaggio, that is, the fundamental frequency range of approximately 300–400 Hz, applying either of the two singing strategies that are typically used (1) in classical and (2) in nonclassical singing, respectively. Formant frequencies of each note in the scales were measured by inverse-filtering the acoustic signal. In the classical style, the first formant tended to be lower than in the nonclassical style. Neither the first nor the second formant tended to change systematically between scale tones, such that on some scale tones either or both formants was just below, just above, or right on a spectrum partial. In many cases, singers produced similar spectrum characteristics of the top tones of the scales with different first and second formant frequencies. Regardless of whether the first formant was slightly lower, slightly higher, or right on a partial, the properties of the voice source did not seem to be affected.
  • Publicación
    Long-Term Average Spectrum Characteristics of Portuguese Fado-Canção from Coimbra
    (Elsevier, 2023-07) Filipa M.B., Lã; Silva, Luciano S.; Granqvist, Svante; Filipa M.B., Lã
    Descriptions of acoustical characteristics of Fado, a Portuguese urban style sung in Lisbon and Oporto, are scarce, particularly concerning Fado-Can¸c~ao, a related style sung in Coimbra. The present study aims at describing long-term average spectrum (LTAS) parameters of 16 professional singers while singing and reading the lyrics of a typical Fado-Can¸c~ao. LTAS parameters were investigated in terms of: (1) equivalent sound level (Leq); (2) spectral differences between 3 frequency bands 0−2, 2−5, and 5−8 kHz; and (3) quantification of spectral prominence between 2 and 4 kHz, calculated as the level difference between the peak in this frequency region and a reference trendline between 1 and 5 kHz, henceforth Formant Cluster Prominence (FCP). Given that Fado-Can¸c~ao, besides Fado and traditional styles, originated also from classical singing, and that previous studies on Fado suggest the absence of a singer’s formant cluster, the averaged LTAS for all Fado-Can¸c~ao singers was further compared to the LTAS of two world-touring opera baritones singing an operatic aria and a lied. Results show that Fado-Can¸c~ao is commonly sung with a Leq of 86.4 dB and a FCP of about 10 dB, values significantly higher when compared to reading. The FCP in Fado-Can¸c~ao, although smaller than for the two classical opera singers’ examples (14.8 and 20 dB, respectively), suggests that the style preserved some of its original lyrical influence. However, because younger singers present higher energy in the 5−8 kHz region relative to the remaining frequency bands as compared to older singers, it seems that Fado-Can¸c~ao may be drifting towards non-classical vocal practices. FCP seems to be a promising straightforward method to quantify the degree of formant clustering around the region of the singer’s formant in LTAS, allowing comparisons between different singers and singing styles.
  • Publicación
    Fundamental frequency variations across the menstrual cycle and the use of an oral contraceptive pill use
    (American Speech-Language-Hearing Association (ASHA), 2020-04-27) Filipa M.B., Lã; Polo Cano, Nuria; Filipa M.B., Lã
    Purpose Concentrations of sex steroid hormones—estrogens, progesterone, and testosterone—have been associated with premenstrual and menstrual vocal symptoms. However, the extent to which these symptoms may be reflected on acoustical features of the voice is still debated. This study investigates variations in fundamental frequency (fo) and related parameters in connected speech across phases of the menstrual cycle and during the use of a combined oral contraceptive pill (OCP). Method Electrolaryngographic recordings were made, and blood samples were collected at three different phases of the menstrual cycle—menstrual, follicular, and luteal—for placebo and OCP use. These two conditions were blindly and randomly allocated in the study. Speaking fo (SFF), SFF standard deviation, SFF rate of change, SFF slope, maximum and minimum fo, and fo range were extracted for nine healthy females while reading a phrase from the Rainbow Passage. Concentrations of sex hormones were analyzed in serum. Nonparametric statistical tests were carried out to assess differences between phases and conditions. Results SFF, its standard deviation, and maximum fo were significantly different between phases of the menstrual cycle for placebo use only. Menstrual phase showed the lowest values. Maximum and minimum fo were significantly different between placebo and OCP use for menstrual and follicular phases, respectively. Conclusions Fluctuations in sex steroid hormones across the menstrual cycle alter fo in speech more than a particular hormonal concentration. OCP use seems to have a stabilizing effect on the voice relative to fo and related parameters in speech.
  • Publicación
    Real-Time visual feedback in singing pedagogy: current trends and future directions
    (MDPI, 2022-10-25) Filipa M.B., Lã; Barro Fiuza, Mauro; Filipa M.B., Lã
    Singing pedagogy has increasingly adopted guide awareness through the use of meaningful real-time visual feedback. Technology typically used to study the voice can also be applied in a singing lesson, aiming at facilitating students’ awareness of the three subsystems involved in voice production—breathing, oscillatory and resonatory—and their underlying physiological, aerodynamical and acoustical mechanisms. Given the variety of real-time visual feedback tools, this article provides a comprehensive overview of such tools and their current and future pedagogical applications in the voice studio. The rationale for using real-time visual feedback is discussed, including both the theoretical and practical applications of visualizing physiological, aerodynamical and acoustical aspects of voice production. The monitorization of breathing patterns is presented, displaying lung volume as the sum of abdominal and ribcage movements signals. In addition, estimates of subglottal pressure are visually displayed using a subglottal pressure meter to assist with the shaping of musical phrases in singing. As to what concerns vibratory patterns of the vocal folds and phonatory airflow, the use of electroglottography and inverse filters is applied to monitor the phonation types, voice breaks, pitch and intensity range of singers of different music genres. These vocal features, together with intentional voice distortions and intonation adjustments, are also displayed using spectrographs. As the voice is invisible to the eye, the use of real-time visual feedback is proposed as a key pedagogical approach in current and future singing lessons. The use of such an approach corroborates the current trend of developing evidence-based practices in voice education.
  • 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., Lã
    Objectives: 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 partial
  • Publicación
    Development and Validation of the Singing Voice Function Self-Efficacy Scale (Singing-VoSES)
    (['SAGE', 'SEMPRE'], 2023-02-11) Filipa M.B., Lã; Barro Fiuza, Mauro; Ardura Martínez, Diego; Filipa M.B., Lã
    This investigation aimed at developing and validating a scale measuring perceived self-efficacy in singing with respect to voice function, the Singing Voice Function Self-Efficacy Scale (Singing-VoSES). Voice experts validated an 18-item scale, subsequently administered online, targeting specifically professional and semi-professional female singers. These inclusion criteria were met by a total of 439 participants. Results of both exploratory and confirmatory factorial analysis suggest that Singing-VoSES is a valid scale, with items grouped into three self-efficacy dimensions: Higher Range and Transitions, Middle Range and Lower Range. Middle Range and Lower Range dimensions were both significantly higher than Higher Range and Transitions. Singing high notes and notes within transitional vocal ranges require a refined neuromotor control of the voice, and thus may be particularly challenging. Comparisons between pre and postmenopausal singers were made, as menopause has been associated with changes in voice function. Significantly lower self-efficacies for Higher Range and Transitions and Middle Range were found in post as compared to premenopausal singers. This result, together with the possible lack of coping strategies, may contribute to negative impacts on singers’ performances and, ultimately, lead to premature retirement from public performances. Thus, monitoring self-efficacy with respect to voice function seems relevant, particularly when assisting singers experiencing menopause-related voice difficulties.
  • Publicación
    Singing at menopause: a systematic review with pedagogical implications
    (SAGE, 2021-12-16) Sevillano García, María Luisa; Filipa M.B., Lã; Barro Fiuza, Mauro; Filipa M.B., Lã
    Menopause is a certainty in a female singer’s life; depletion of estrogens may lead to physical, mental, and vocal symptoms. To investigate the extent to which these symptoms affect singers, a systematic literature review was carried out using eight interdisciplinary bibliographic databases. Combinations of the following key words were used: menopause, climacterium, singing, singers, and choir. From 18 studies, including three doctoral dissertations and a master’s thesis, only 10 met the inclusion criteria. The heterogeneity of study designs and methods of data collection and analysis precluded the carrying out of a meta-analysis. Instead, descriptors of symptoms affecting the voice, and vocal characteristics associated with menopause (menopause descriptors) were categorized, and their frequency of occurrence determined, according to six types of primary dataset: (1) self-reported symptoms, (2) acoustic characteristics, (3) observations of the larynx, (4) perceptual evaluations, (5) analysis of electrolaryngographic waveform characteristics, and (6) analysis of hormone concentrations. The descriptors that occurred most frequently in the literature concerned aspects of voice production, whereas those concerning vocal health, and vocal practice and performance, were less common. Of the three subsystems that comprise the vocal instrument, the vibrating vocal folds seem to be more affected than breathing and resonance. Changes in vocal range, timbre, endurance, and vocal fold mobility occur during menopause, affecting singers’ voice quality. Some singers reported that their ability to perform was compromised, mainly due to memory lapses and lack of confidence. Maintaining regular singing and practicing semi-occluded vocal tract exercises throughout the menopausal transition seem to help singers to overcome the negative impacts of menopause on vocal performance.
  • Publicación
    Contact quotient versus closed quotient: a comparative study on professional male singers
    (Elsevier, 2015-03) Filipa M.B., Lã; Sundberg, Johan; Filipa M.B., Lã
    Objectives: 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.
  • Publicación
    Pain prevalence in instrumentalist musicians: a systematic review
    (Science & Medicine, Inc., 2015-03-01) Silva, Anabela G.; Filipa M.B., Lã; Afreixo, Vera; Filipa M.B., Lã
    Objective: To inform on current prevalence of pain amongst different musicians groups, sex and body region. Methods: Studies were sought from PubMed, Web of Science; Academic Search Complete, Science Direct and Scielo. Databases were searched since 1st January 2000 until December 2012. Two reviewers screened titles and abstracts, and assessed full reports for potentially eligible studies. One reviewer extracted information on musicians’ characteristics, study methods and study quality. When possible a meta-analysis of pain prevalence estimates was performed. Results: A total of 18 studies were included in this systematic review. Studies assessed pain prevalence in general and the prevalence of pain affecting playing capacity for different time periods (point prevalence, one week prevalence, one year prevalence, month prevalence and lifetime prevalence). The prevalence of pain in general, across all groups of musicians and periods of interest over which pain was assessed varied between 29.0% and 90.0%, whereas the prevalence of pain affecting playing capacity varied between 25.8% and 84.4%. There was a tendency for guitar players to have the highest pain prevalence. The most affected body regions were low back (9.8% - 66.7%) and neck (9.8% - 48.5%). Conclusions: Pain prevalence is high among musicians, independently of the pain definition used. Health and educational policy makers should become aware of the high lifetime pain prevalence affecting performance practices, so that pain associated mechanisms are investigated and preventive strategies can be implemented and tested.
  • Publicación
    Kulning: Acoustic and Perceptual Characteristics of a Calling Style Used Within the Scandinavian Herding Tradition
    (Elsevier, 2022-01-03) Rosenberg, Susanne; Sundberg, Johan; Filipa M.B., Lã; Filipa M.B., Lã
    Kulning, a loud, high-pitched vocal calling technique pertaining to the Scandinavian herding system, has attracted several researchers' attention, mainly focusing on cultural, phonatory and musical aspects. Less attention has been paid to the spectral and physiological properties that characterize Kulning tones, and also if there is a physiologically optimum pitch range. We analyzed tones produced by ten participants with varying experience in Kulning. They performed a phrase, pitch range G5 to C6 (784 to 1046 Hz), in three different conditions: starting (1) on pitch A5, (2) on the participant's preferred pitch, and (3) after the deepest possible inhalation, also on the participant's preferred pitch subglottal pressure (Psub) was measured as the oral pressure during /p/-occlusion. The quality of the Kulning was rated by a group of experts. The highest-rated tones all had a sound pressure level (SPL) at 0.3 m exceeding 115 dB and a pitch higher than 1010 Hz, while the SPL of the lowest rated tones was less than 108 dB at a pitch below 900 Hz. A multiple regression analysis was performed to evaluate the relationship between the ratings and Psub), SPL, level of the fundamental and the frequency at which a spectrum envelope dip occurred. Highly rated tones were started at maximum lung volumes, and on participants’ preferred pitches. They all shared a high frequency of the spectrum envelope dip and a high level of the fundamental. In decreasing order of ratings, Condition 3 showed the highest values followed by Condition 2 and Condition 1. Each singer seemed to perform best within an individual Psub and pitch range. The relevance of the results to voice pedagogy, artistic, and compositional work is discussed.