Digital Signal Processing Reference
In-Depth Information
Also, instead of using the script
LV
_
LT I of X
, use the function
filter
, with input argument
a
=
1 and
b
equal to the input argument
LT ICoeff
as would have been used with
LV
_
LT I of X
. Since the
result is complex, plot the absolute value of the result of the filtering operation.
Figure 2.30 shows the result from this alternate procedure, using the parameters specified at (e)
3
2.5
2
1.5
1
0.5
0
0
1000
2000
3000
4000
5000
Frequency, Hz
Figure 2.30:
An estimate of the frequency response between source and listening points in a room,
modeled with a direct and two reflected paths. The first reflected path is only one sample longer in
duration than the direct path. The second reflected path is only one sample of delay longer than the first
reflected path. Both reflected waves arrive at the same amplitude as that of the direct wave.
above. Figure 2.31 (resulting from the call at (f ) above) shows what happens when the first reflected path
is severely attenuated, as perhaps by an acoustic absorber inserted into the path to alter the frequency
response at the listening point.
