Speech Processing by Computer
LECTURE
1
SAMPLING
AND EDITING
By the end of the
session you should:
q
be
able to describe what ADC and DAC devices do
q be able to describe the filtering, sampling and
quantisation stages of analogue to digital conversion
q have a qualitative understanding of how
sampling rate and quantisation accuracy affects signal quality
q know what is meant by aliasing and quantisation
noise
q appreciate the need for good signal management
Outline
1.
Sampling and
Editing
1.1. Analogue vs. Digital
1.1.1.
Storage as
analogy
1.1.2.
Storage as
encoding
1.2. Analogue to Digital Conversion
1.2.1.
Pre-filtering
1.2.2.
Sample and Hold
1.2.3.
Voltage
comparison
1.3. Digital to Analogue Conversion
1.3.1.
Adding voltages
1.3.2.
Post-filtering
1.4. Sampling Theorem
1.4.1.
Selection of
sampling rate
1.5. Quantisation
1.5.1.
Selection of
sampling accuracy
1.6. Editing
1.6.1.
Management of
recordings
1.6.2.
Annotation
1.6.3.
Cutting and
Pasting
Rosen
& Howell, Signals and Systems for Speech and Hearing, Chapter 14,
Academic Press, 1990.