Univ. Oslo and Statsbygg
Abstract :
The attack of a signal is of course best preserved if we hear the direct
sound only, but that is not the case even in a small room. Musicians
know
how long reverberation masks the next onset, but more astonishing is
the
prolongation of the attack, also for a first note in a phrase.
The paper will present theory regarding how diffuse field
reverberation
influences the attack. The early response of a concert hall, is,
however,
seldom “diffuse”, and it is shown that introducing early reflection can
reduce the smoothening from the reverberation.
The paper shows measurements of attack from the Integrated
Squared
Step Response, for both real halls and simulations, and for signals of
different lengths and for different musical instruments. Very short
notes/clicks/xylophone gets almost no prolongation of the attack due
to
reverberation. Medium long notes get prolonged attack, which makes
them sound somewhat less brilliant. For double bass arco etc. with
long
note on-set, the attack is also prolonged, but the timbre might be
even
smoother and more pleasant.
Preserving the attack is important because listeners nowadays are
used
to recordings where any wanted amount of direct sound is mixed with
a
late, long smooth, non-correlated reverberation.