Player noise was calculated from the FFT spectra by measuring the dB minima located between the dB maxima, which can be attributed to the harmonics of the recorded tone. Power spectra were generated using the fast Fourier transformation (FFT) function of Praat, and displayed as frequency (unit = Hz)-dependent intensity (unit = dB) spectra (power spectra). Segments 1 s in length of these recordings (wav files with a sample rate of 44 kHz) during stable tone generation were used for analysis with Praat. the microphone was defined and remained unchanged during all recordings. The equipment was set up to record pure signals without any effects this set-up was unaltered during all recordings. The recordings of the acoustic waves were carried out using the following equipment: Rode NT5 microphone (Rode, Silverwater, Australia), Behringer XENYX 1204 USB Mixer (Behringer, Willich, Germany), Mixcraft 8 Pro Studio recording software (Acoustica, Oakhurst, CA, USA), and Praat analysis software. The playing, recording, and analysis of acoustic waves, and the determination of acoustic parameters such as power spectra (frequency-dependent intensity spectra), player noise, formant expression, intensity shimmer, and frequency jitter of the recorded acoustic signals were performed under conditions and with equipment as described previously. The relevance of this effect for the live performance of music where complex superimposition of acoustic waves radiated by the same or different instruments may occur is further evaluated and discussed. Based on recordings with experienced tenor saxophone players it is demonstrated in this study that a sound bridge mounted to the saxophone (see Figure 1) results in a significant increase of the frequency-jitter of the radiated acoustic waves. The aim is to identify which variations of the acoustic waves are induced by the mounted bridge, and whether these variations might be useful to propose an explanation for the audible effects described by professional musicians and conductors. In this study, the jitter of the played tone is investigated in detail, as significant changes in this parameter could be detected with the use of a mounted bridge on a tenor saxophone. As it has been shown that these parameters are relevant for the emitted sound and are controlled, to some extent, by professional players, it might be the case that a mounted bridge either affects these parameters directly or influences the interaction between the player and the instrument, which may result in changes in the above-mentioned parameters. Short time fluctuations of the emitted acoustic energy (shimmer) or of the audible and measurable frequency (jitter) may undergo changes due to the use of a mounted bridge. Other parameters, such as the expression of certain formants and noise, as part of the sound generated by the player, might be affected by the mounting of a bridge on the instrument. It has been reported that professional saxophone players can adjust their vocal tract to achieve and optimize the output of the generated acoustic radiation and, in general, have a high capability to influence their sound. Thus, the effect must result from changes in other characteristics of the radiated acoustic wave. A change in intonation as a consequence of mounting the metal bridge can be excluded from causing the audible effect, as players tune their instrument with the bridge mounted. The data further indicate that the occasionally hearable “rumble” of a wind instrument orchestra with instruments showing slight differences in the frequency of the harmonics might be reduced (or avoided), if the radiated acoustic waves have a systematic jitter of a certain magnitude.įollowing the fundamentals of acoustics, the mounting of such a bridge must influence and modify the radiated acoustic wave of a played wind instrument, in order to generate a difference in sound, which can be heard. Simulations with artificially generated acoustic waves confirm that acoustic waves with a certain systematic jitter show less cancelling of the acoustic energy under a phase-shifted superimposition, compared to acoustic waves with no frequency jitter thus, being beneficial for live performances in small halls with minimal acoustic optimization. Through simulated phase-shifted superimpositions of the recorded waves, it is shown that the cancellation of acoustic energy due to antiphase superimposition is significantly reduced in recordings with the bridge. It is shown that a gold-plated device mounted on a tenor saxophone, forming a small bridge between the mouthpiece and the S-bow, can change two characteristics of the radiated sound: (1) the radiated acoustic energy of the harmonics with emission maxima around 1500–3000 Hz, which is slightly reduced for tones played in the lower register of the saxophone (2) the frequency jitter of all tones in the regular and upper register of the saxophone show a two-fold increase.
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