Influence of recording technique and ensemble size on apparent source width

The impression of listeners to aurally “see” the size of a performing entity is crucial to the success of both a concert hall and a reproduced sound field. Previous studies have looked at how different concert halls with different lateral reflections affect apparent source width. Yet, the perceptual effects of different source distributions with different capturing techniques on apparent source width are not well understood. This study explores how listeners perceive the width of a symphony orchestra by using four stereo and one binaural recording techniques and three wave field synthesis ensemble settings. Beethoven’s Symphony No. 8, performed by wave field synthesis in three ensemble settings, was recorded using these five recording techniques and at two distances in EMPAC concert hall. Subjective experiments were conducted using stereo loudspeakers and headphone to play back the recording clips asking the listeners to rate the perceived wideness of the sound source. Results show that recording techniques greatly influence how wide an orchestra is perceived. The primary mechanism used in judging auditory spatial impression differs between stereo loudspeaker and headphone listening. When well-written symphonic music is recorded and reproduced by two-channel stereophony, the changes in instrument positions in terms of increasing or reducing the physical source width do not lead to an obvious increase or reduction on the spatial impression of the performing entity.