A single loudspeaker with frequency-dependent directivity
characteristics, positioned in a room of normal size with
frequency-dependent absorption coefficients of the room surfaces,
has been simulated using an electroacoustic setup. The model
included the direct sound, seventeen individual reflections and
the reverberant field. The threshold of detection, and
just-noticeable differences for an increase in level were measured
for individual reflections. The results have confirmed that the
first-order floor reflection is likely to contribute individually
to the timbre of reproduced noise. However, for a speech signal
none of the investigated reflections will contribute individually
to the timbre. It is suggested that the threshold of detection is
determined by the spectral changes in the dominant frequency range
of 500 Hz to 2 kHz. For increases in the level of individual
reflections, the most likely to be audible is the first-order
floor reflection, for speech and noise. For a noise signal,
additional reflections from the wall to the left and behind the
listener also belong to this group.
Copyright (1996) Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America.
This work was carried out while the author was still at the department.