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Bassoon Directivity Data
(2020)
Room acoustic conditions are an inherent element of every live music performance. They interact with the sound that is generated by the musicians, modifying the characteristics of the sound received by audience and musicians. While listeners usually play a passive role in the context of a live performance, musicians are part of a feedback loop composed by themselves, their instruments, and the room. The goal of this thesis is to characterize the effects of room acoustics in live performances, by studying the acoustical preferences of musicians and characterizing potential performance adjustments implemented by solo players while adapting their interpretation to the room acoustic conditions.
To conduct systematic experiments, a virtual acoustic environment that replicates acoustic conditions of real rooms in laboratory conditions is implemented. Room impulse responses of performance rooms are measured and parametrized using spatial measurement techniques. The responses are later resynthesized and convolved in real-time with the sound generated by a musician. The resulting sound is reproduced through a 3D loudspeaker set-up, allowing musicians to perform under replicated acoustic conditions of measured rooms in real-time. The system is used to conduct pilot studies on stage acoustics preferences of semi-professional trumpet players, and to study the impact of room acoustics on potential performance adjustments of live performance. To this end, musical pieces are recorded under different acoustic conditions and later analyzed. A second experiment is performed with organ players in the Detmold Konzerthaus. The reverberation time of the hall is modified using a reverberation enhancement system, and live performances are recorded under different acoustic conditions using a MIDI interface. Similarly to the trumpet players, the recordings are analyzed to evaluate the extent of the performance adjustments. Finally, listening tests are conducted to assess the perceived impact of those adjustments by listeners.
Results of the experiments suggest that musicians systematically adjust their performance to accommodate room acoustic conditions and listeners are generally able to perceive these changes. Trumpet players tend to decrease the sound level and sound brightness when exposed to longer and stronger reverberation. Some players adjust as well musical dynamics and aspects related to the tempo of their performance, although generalized trends are not observed. Dry environments are usually preferred to practice instrument technique, while longer reverberation times are preferred in concert conditions. Additionally, the presence of a sufficient amount of early energy contributes positively to the musicians’ comfort, regardless of the direction of incidence of this sound energy. Organ players are prone to modifying the temporal aspects of the performance, generally decreasing the overall tempo and increasing the length of breaks in more reverberant environments. The musical character of the played excerpts seems to play an important role, and while for some pieces changes are generalized and systematic, the performance of other pieces with soft dynamics and little contrast is generally less affected by room acoustics.
Reverberation is an important factor of the acoustics in a room. It influences the
acoustic perception of the listener and the performer. Each concert venue has its
specific acoustic properties. Numerous studies regarding these properties have been
conducted, mostly in real world or fully synthesized environments. However, both
acoustic quality and perception in concert spaces are still not satisfactorily explained.
The present thesis contributes new findings in the field of reverberation (late energy)
for concert spaces. Previous concepts are further refined and novel approaches
suggested. Several experiments are conducted in semi-virtual acoustics, namely real
rooms whose existing acoustics is altered by means of an electronic reverberation
system with loudspeakers. Thus, the possibility of changing the acoustic situation at the push of a button is offered, while the listeners’ visual and tactile perception remains the one from the real world environment. A lecture hall and a medium-sized concert
hall equipped with enhancement systems are the test environments. Three aspects of
reverberation are studied using this technique among others: reverberation level, spatial distribution of reverberation and the connection between signal dynamics and acoustics.
The related perceptual attributes reverberance, listener envelopment and perception of dynamics are investigated by means of listening experiments.
Following a qualitative investigation on enhancement systems, it is observed that
reverberance depends highly on reverberation level. The method of only assessing
decay time is not suffcient. An energy parameter such as strength must be included to
predict reverberance. A loudness-based reverberation analysis is further explored and found to perform well in principle, however the three loudness models investigated
differ noticeably. The direction of late reverberation in concert halls and the influence on the feeling of envelopment is further specified. Several tests show that the current
measure neglects late reverberation from behind and above which contribute to listener envelopment. Lastly, the connection between signal envelope or dynamics and room
acoustics is investigated, specifically regarding reverberation. Studies are conducted using, for example, a constant virtual orchestra source or a large pool of audio recordings from concert halls and opera houses. It is observed that reverberation alters the signal dynamic considerably, which is vital both in the context of acoustics and performance practice.