Physical properties of treble recorder tones suitable for baroque music
Yoshinori Ando, Tatsuro Shima · The Journal of the Acoustical Society of America · 1978
Using real and synthesized tones, we have investigated how the quality of treble recorder tones depends on their physical properties, such as harmonic structure, nonperiodic amplitude and frequency fluctuations of overtones, and noise content. By the use of a paired comparison method, the quality of the tones was judged by professional recorder players and by amateurs with some musical training. As the result, psychological interval scales of quality were constructed against (1) two parameters of harmonic structure, (2) magnitude and frequency structure of harmonic's amplitude fluctuation and (3) those of harmonic's frequency fluctuations. The best quantities are as follows: (1) Decay rate of harmonic amplitude is 4 dB/harmonic. (2) The second, fourth and sixth harmonics are some 10 dB weaker than the values calculated from this decay rate. (3) Frequency fluctuation magnitude of the second and third harmonics is about 1.7% expressed in effective value. Frequency fluctuation of the higher harmonics is rather harmful for quality.