Concert halls with strong lateral reflections enhance musical dynamics

Abstract

One of the most thrilling cultural experiences is to hear live symphonyorchestra music build up from a whispering passage to a monumental fortissimo. The impact of such a crescendo has been thought to depend only on the musicians' skill, but here we show that interactions between the concert-hall acoustics and listeners' hearing also play a major role in musical dynamics. These interactions contribute to the shoebox-type concert hall's established success, but little prior research has been devoted to dynamic expression in this three-part transmission chain as a complete system. More forceful orchestral playing disproportionately excites high frequency harmonics more than those near the note's fundamental. This effect results in not only more sound energy, but also a different tone color. The concert hall transmits this sound, and the room geometry defines from which directions acoustic reflections arrive at the listener. Binaural directional hearing emphasizes high frequencies more when sound arrives from the sides of the head rather than from the median plane. Simultaneously, these same frequencies are emphasized by higher orchestral-playing dynamics. When the room geometry provides reflections from these directions, the perceived dynamic range is enhanced. Current room-acoustic evaluation methods assume linear behavior and thus neglect this effect. The hypothesis presented here is that the auditory excitation by reflections is emphasized with an orchestra forte most in concert halls with strong lateral reflections. The enhanced dynamic range provides an explanation for the success of rectangularly shaped concert-hall geometry.perception | performance | architecture

Perception of music dynamics in concert hall acoustics

“…The general results suggest that a strong and lateral sound field enhances the perceptual dynamic effects, which provides evidence also for earlier studies on the musical dynamic range of concert halls. 5 The outcome of the experiment offers also an explanation for the subjective rank-ordering of acoustic quality, 7 as certain halls with a reputation of outstanding acoustics appear to provide strong perceptual responsiveness to varying music dynamics, thus, rendering a more expressive listening experience.…”

“…For instance, paths of sound propagation that are particularly sensitive to higher frequencies due to the directional hearing become perceptually more significant with the change of signal spectrum. 5 Together the source, path, and receiver form a non-linear system, 6 where the room acoustics may affect the perception of music dynamics in many aspects.…”

“…Therefore, the music dynamics affects both the level and spectrum of the signal exciting the room, while the frequency-dependency of spatial hearing and spectral masking 30 gives significance to the reflection directions and the room geometry. 5,23,24 Authors such as Meyer and Beranek, have pointed out the importance of the concert halls' response to music dynamics. They have stated that, first, while quiet dynamics can be acceptable in poor halls, the high quality of forte is an indication of an acoustically good hall (Ref.…”

“…P€ atynen et al showed an objective study where rooms with lateral early reflections enhance the transmission of the dynamic range in music to the listeners' ears. 5 These observations propose that the concert halls may transmit music dynamics differently, and also that the rendering of music dynamics could be a substantial factor in the overall room acoustic quality. Still, the subjective perception of the dynamic response has remained unexplored.…”

The acoustics of a concert hall as a linear problem

“…2 the mean difference is only a few decibels, this difference is notably in the same frequency region where the loud orchestra music has more energy than the quietly played music (dashed curve). In summary, when walls and ceiling of a concert hall attenuate high frequencies as little as possible and when the first early reflections are bounces from the sidewalls, the change of the spectrum of orchestral music makes the largest perceived crescendo [7]. Furthermore, auditory masking also plays a role here, but due to its complexity we leave it out in this context.…”