Sensitivity of stage acoustic parameters to source and receiver directivity: Measurements on three stages and in two orchestra pits. (August 2017)

• Record Type: Journal Article
• Authors: Wenmaekers, R.H.C.; Hak, C.C.J.M.; Hornikx, M.C.J.; Kohlrausch, A.G.
• Is Part Of: Applied acoustics. Volume 123(2017)
• Page Start: 20
• Page End: 28
• Publication Date: 2017-08
• Subjects: Stage acoustics -- Support parameters -- Dodecahedron -- Directivity -- Head and torso simulator -- Symphony orchestra; Acoustical engineering -- Periodicals; Periodicals; 620.2
• DOI: 10.1016/j.apacoust.2017.03.004
• Languages: English
• ISSNs: 0003-682X

Abstract

Graphical abstract: Highlights: A directional loudspeaker and dummy head are used for stage acoustics measurements. Reverberation time T20 and EDT and support STearly, d and STlate, d have been measured. Results based on 3800 impulse responses of three stages and two orchestra pits. Variation in parameter results are explained by location of strongest reflection. Differences noticeable for EDT and T20 and unnoticeable for STearly, d and STlate, d . Abstract: Stage acoustic parameters are commonly determined in concert halls using omnidirectional transducers, but might be more valid when using directional transducers. In this paper, the sensitivity of stage acoustic parameters to source and receiver directivity has been investigated by measurements on three stages and in two orchestra pits. A single loudspeaker was used with a directivity similar to a trumpet, aimed in 12 evenly spread directions. As a directional receiver, a head and torso simulator (HATS) was used with its viewing direction towards the conductor position. Measurements were also taken with (nearly) omnidirectional transducers. i.e. a dodecahedron loudspeaker and a single microphone. The investigated stage acoustic parameters measuring reverberation time and reflected sound levels were sensitive to the directivity of the measurement transducers. The parameters dealing with early sound, EDT and ST early, d, are more sensitive than the parameters dealing with late sound, T 20 and ST late, d . When comparing results measured with a head and torso simulator to results measured with an omnidirectional microphone, the EDT tends to be lower and the ST early, d higher for the ear directed towards the sound source. The results of measurement using the directional source show that EDT and T 20 have lowest values and ST early, d and ST late, d highest values, when the sound source is directed towards the closest surfaces that cause a first order reflection towards the receiver. Further research is necessary to determine whether the differences in parameter values would lead to noticeable differences.