Aerodynamic Parameters in Byzantine Chant Voices: Comparisons Across Pitch and Loudness.

OBJECTIVE: This study was designed to assess the impact of phonation frequency and loudness increase on aerodynamic parameters of the singing voice in Byzantine chant (BC). DESIGN: Aerodynamic measurements in BC were obtained and statistically analyzed. METHOD: Fifteen experienced BC chanters, all baritones, performed the ascending notes G2, C3, E3, G3, C4, E4, and G4, at normal and high levels of loudness within a mask, while repeating strings of /pi/ syllables. The parameters of airflow (FR), subglottal pressure (Psub), and sound pressure level (SPL) were directly measured, and from them, the glottal flow resistance (Rg) and vocal efficiency (VE) were calculated. All the parameters' values were statistically analyzed. RESULTS: Statistically significant differences for FR, Psub, and SPL parameters in BC between the two loudness levels, at constant pitch, and for Psub, SPL, Rg, and VE among different pitches, at constant loudness levels were detected. When loudness increases, a) only the mean values of FR, Psub, and SPL, within C3-C4, increase, whereas those of Rg and VE do not show any change, and b) at G2, only the mean Psub increases, while in the upper range E4-G4, both mean SPL and mean VE decrease. When pitch is raised, a) for each level of loudness, within G2-E4 pitch range, the means of Psub, SPL, Rg, and VE increase while this is not the case for FR, and b) in the highest range (E4-G4), average SPL and VE drop while Rg and Psub remain stable. Our findings suggest that: a) most participants increase Psub and SPL without modification of Rg when loudness increases, and b) most participants increase both SPL and Psub while changing Rg with pitch rise. Idiosyncratic differences among the participants were detected in Rg and Psub, because of pitch rise, and, also, in Rg and VE due to loudness increase. CONCLUSIONS: The results from this study reveal that, within the C3-C4 pitch range: a) there is independent control between the loudness and glottal adduction, and b) Psub is the main tool for increasing both the loudness and SPL. For some exceptions among the participants, either the Rg alteration or other modifications of the vocal system are, possibly, the cause of the loudness increase. The increased mean values of SPL, Rg, and Psub with pitch rise, for most participants, suggest that both glottal adduction and Psub increase together with the SPL and pitch increase. The VE increase within G2-E4 pitches reaches a maximum value at E4. Some exceptions among the participants exist that suggest the possible use of different phonatory strategies when changing either the pitch or the vocal loudness.

On Exploring Vocal Ornamentation in Byzantine Chant.

OBJECTIVES: A special vocal ornament in Byzantine chant (BC), the single cycle ornamentation structure (SCOS), is defined and compared with the vibrato with respect to its time (rate, extent) and spectral (slope [SS], relative speaker's formant [SPF] level, formant frequencies [Fi] and bandwidths [Bi], and noise-to-harmonics ratio [NHR]) characteristics. STUDY DESIGN: This is a comparative study between the vocal ornaments of SCOS and vibrato, of which time and spectral acoustic parameters were measured, statistically analyzed, and compared. METHODS: From the same hymn recordings chanted by four chanters, the SS, SPF level, FFi, FBi, and NHR difference values between the vocal ornament and its neighbor steady note, and the rate and extent, were compared with those of vibrato. RESULTS: The mean extent values for SCOS were found to be almost double the corresponding values for vibrato, and the rate of SCOS tends to be different from the rate of vibrato. The difference values of: 1) the NHR, 2) the spectral slope, and 3) the SPF level, between the vocal ornament and its neighbor steady note were found to be: 1) higher for SCOS, 2) mainly lower for SCOS, and 3) lower for SCOS, respectively. No significant differences were detected for the FFi and FBi. The FF1 differences tend to be negative in both ornaments indicating a formant tuning effect. CONCLUSIONS: A new vocal ornament (SCOS) in BC is studied, of which the extent, NHR (HNR), the spectral slope, and the SPF level are different compared to those of vibrato.

Acoustic characteristics of modern Greek Orthodox Church music.

OBJECTIVES: Some acoustic characteristics of the two types of vocal music of the Greek Orthodox Church Music, the Byzantine chant (BC) and ecclesiastical speech (ES), are studied in relation to the common Greek speech and the Western opera. STUDY DESIGN: Vocal samples were obtained, and their acoustic parameters of sound pressure level (SPL), fundamental frequency (F0), and the long-time average spectrum (LTAS) characteristics were analyzed. METHOD: Twenty chanters, including two chanters-singers of opera, sang (BC) and read (ES) the same hymn of Byzantine music (BM), the two opera singers sang the same aria of opera, and common speech samples were obtained, and all audio were analyzed. RESULTS: The distribution of SPL values showed that the BC and ES have higher SPL by 9 and 12 dB, respectively, than common speech. The average F0 in ES tends to be lower than the common speech, and the smallest standard deviation (SD) of F0 values characterizes its monotonicity. The tone-scale intervals of BC are close enough to the currently accepted theory with SD equal to 0.24 semitones. The rate and extent of vibrato, which is rare in BC, equals 4.1 Hz and 0.6 semitones, respectively. The average LTAS slope is greatest in BC (+4.5 dB) but smaller than in opera (+5.7 dB). In both BC and ES, instead of a singer's formant appearing in an opera voice, a speaker's formant (SPF) was observed around 3300 Hz, with relative levels of +6.3 and +4.6 dB, respectively. CONCLUSIONS: The two vocal types of BM, BC, and ES differ both to each other and common Greek speech and opera style regarding SPL, the mean and SD of F0, the LTAS slope, and the relative level of SPF.

Acoustic analysis of musical intervals in modern Byzantine Chant scales.

The goal of this work is to investigate experimentally the music intervals in modern Byzantine Chant performance and to compare the obtained results with the equal temperament scales introduced by the Patriarchal Music Committee (PMC). Current measurements resulted from pressure and electroglottographic recordings of 13 famous chanters singing scales of all the music genera. The scales' microintervals were derived after pitch detection based on autocorrelation, cepstrum, and harmonic product spectrum analysis. The microintervallic differences between the experimental values and the PMC's ones were statistically analyzed indicating large deviation of the mean values and the standard deviations. Significant interaction effects were identified among some genera and between ascending and descending scale directions.