Noise quality of transient sounds: Perception of ‘‘hiss’’ and ‘‘cough’’ in a flue organ pipe

Abstract

According to an expert organ builder, the onomatopoeia ‘‘hiss’’ and ‘‘cough’’ must be distinguished from the well-known general term ‘‘chiff’’ in order to describe the characteristic bursts of noise occuring during the transient of many flue organ pipes. These particular sounds can be adjusted and aligned to a certain aesthetic, but this matter has not yet been much discussed by organ experts. This exploratory study mainly relies on a computer-based listening test which has been carried out on two groups of people (musicians and acousticians). The experiment focused on the participants perception of ‘‘hiss’’ and ‘‘cough’’ and also on their ability to extract the ‘‘noisy’’ part from the harmonic components. Even though the sounds were quite similar, the noise/harmonic separation task was successful for a large number of subjects. This supports the hypothesis of a natural perceptual difference between the noise bursts and the concomitant harmonic setup and also the validity of this decomposition. To differentiate and identify ‘‘cough’’ and ‘‘hiss’’ sounds, however, is a much more elaborate task which requires much experience.