Abstract

In an attempt to produce an improved method of displaying the acoustic behaviour of a room, an investigation has been made into some phase-sensitive and correlation methods. In particular a phase-coherent modifcation of the pulsed glide type of display has been developed, in which the microphone output is modulated by the orignial frequency of exictation before being applied to the cathode-ray oscillograph. Tests made using this new instrument are described, and the results discussed. Correlation methods are also discussed and the results of some tests involving cross-correlation are given. Finally modifications of the phase-coherent pulsed glide, making use of cross-correlation and phase-reversal counting are described.