How singers adapt to room acoustical conditions

Abstract

1 INTRODUCTION The perception of musical performers with regard to their acoustical environment, which has received increasing attention since the late 1980s 1, 2 , is different from the perception on the part of the audience. The motor activity of the musician, which absorbs much of his attention, the proximity of his instrument and other instruments as sound source(s), as well as the need to hear him-or herself and other ensemble players sufficiently well for a high quality performance can entail substantially different needs and expectations towards the room acoustical conditions on stage. Recent research has also addressed the question, to what extent and in which way not only the perception but also the way of playing of musical performers depends on the acoustical environment 3-5. In one of these studies, musicians were exposed to different acoustical environments simulated by a multichannel loudspeaker system in an anechoic chamber. As a result, significant differences in terms of tempo, vibrato, and sound level were observed under the different acoustical conditions 6. A comparison of features extracted from the audio signal with the response of the musicians given in questionnaires filled out after the recording indicated that many of the adaptations of the interpretation style were made consciously, such as a more pronounced staccato and longer pauses between notes with increasing reverberation time 7. Another study 8 has been carried out in seven real halls in which a cellist played the same musical program during a concert tour. Room acoustical measurements were performed in the empty rooms, and computer simulations were conducted to estimate the acoustics in the occupied condition. The musical recordings were analyzed in terms of tempo, dynamics, loudness, and timbre characteristics. A statistical analysis of the relationship between room acoustical parameters according to ISO-3382-1 9 and audio features representing qualities of the musical performance revealed that more than 50% of the variance in performance features could be explained by the acoustical properties of the environment. With a similar test design, the same authors invited 12 musical performers playing six musical instruments to perform the same pieces of music in different acoustical conditions, simulated by dynamic binaural synthesis, thus avoiding the confusion with other influencing factors such as the visual impression, audience reactions, or the design of the stage 10. The statistical analysis again revealed a significant influence of room acoustical parameters on the way of playing, but also very individual patterns of reaction, which strongly varied not only between different musical instruments but also between different performers on the same instrument. The interaction of singers with their room acoustical environment was investigated mainly in the context of choir performance. Marshall and Meyer placed an ensemble of singers in a semi-anechoic room, where they were exposed to synthetic sound fields including discrete reflections arriving from the side and rear, combined with an artificial reverberation tail 11. The experiment demonstrated the strong influence of reverberation on the comfort of singers. Early reflections were appreciated if their time delay did not exceed 40 ms, beyond which they became unpleasant. A more recent work 12 focused on the effect of early reflections when singing in small ensembles (2 to 4 singers) in a church. Artificial early reflections were added to the natural acoustics of the venue by means of microphones and loudspeakers. The different groups of singers performed musical pieces