Digital Signal Processing Reference
In-Depth Information
"left"
D ata Trig ger
Relay
FF T
Write
7, 5
5, 0
2, 5
0, 0
-2, 5
-5, 0
Spoken word (time domain )
0. 25
0. 25
0. 50
0. 50
0. 75
0. 75
1. 00
1. 00
s
s
0, 175
0, 150
0, 125
0, 100
0, 075
0, 050
0, 025
0, 000
Spoken word (frequency domain )
250
500
750
1000
1250
1500
1750
2000
2250
2500
2750
3000
3250
3500
3750
Hz
0,10
0,09
0,08
0,07
0,06
0,05
0,04
0,03
0,02
0,01
0,00
0,150
0,125
0,100
0,075
0,050
0,025
0,000
0,07
0,06
0,05
0,04
0,03
0,02
0,01
0,00
0,06
0,05
0,04
0,03
0,02
0,01
0,00
0,10
0,09
0,08
0,07
0,06
0,05
0,04
0,03
0,02
0,01
0,00
Reference spectrum ("data base ")
"up"
"down "
"stop"
"left"
"right "
250
500
750
1000
1250
1500
1750
2000
2250
2500
2750
3000
3250
3500
3750
Y/t Chart 0
Y/t Chart 1
Y/t Chart 2
Y/t Chart 3
Y/t Chart 4
Hz
Illustration 80:
Technical measurement of the reference spectra (amplitude spectra)
At the top you see a suitable circuit for presenting and saving the reference spectra. Here the word "up" is
displayed in the time and frequency domain. Make sure before storing a reference spectrum you designate
the file correctly and set the appropriate path in the menu of the module "Reading Data". It is essential to
proceed carefully.
In order to be able to compare the spectra qualitatively and quantitatively you should include all five refe-
rence spectra in one representation. For this purpose design the lower circuit. The module "Adaptation"
serves to synchronise the data and to check whether all the signals were recorded with the same block
length and sampling rate. In this case, a block length and sample rate of 4096 was set in the menu bar
(A/D). You will see that surprisingly very little happens above 1000 Hz. Select the lens function to examine
this area of the spectrum more closely.
