Relationships of loudness, level, and time structure in pipe organ registrations and design

Abstract

Time-dependent loudnesses and sound pressure levels were measured binaurally from a variety of individual stops and multi-stop registrations of several classical and theater pipe organs covering a wide range of sizes, tonal designs, pipe scalings, wind pressures, and spatial relationships. Studies were also made of modulation in individual low-frequency notes, and in notes and chords affected by the presence or absence of tremulants. Timbres of certain solo stops were assessed in terms of the relationship of specific loudness and sound pressure spectra to their importance in creating subjective timbre. In addition to loudness and sound pressure measurement, advanced analysis by a hearing model (Sottek) and a temporal/tonal pattern-measurement algorithm (‘‘relative approach’’) were employed. Significant differences in the relationship of loudness and level were found depending principally on tonal design, pipe scaling and wind pressures on one hand, and octave-related tonal centers and timbral characteristics of individual stops on the other hand. Consideration was also given to the subjective spatial soundscape resulting from different pipe organ physical layouts and from simultaneous registrations between or among physically-separated speaking divisions.