Audio Engineering

Representation of Audio Signals 457

32

 90

 180

 270

Phase degrees

 360

 450

 540

100 320

Frequency

1 kHz 3.2 kHz 10 kHz

(c)

Figure 15.11(c) : The phase response shows the kind of relative phase shift that might be

responsible.

tidal heights. The accuracy of the shape is dependent on the number of components that
we incorporate and the process can yield a complex wave shape with only a relatively
small number of components. We see here the germ of the idea that will lead to one of the
methods available for achieving data reduction for digitized analogue signals.

4133155177/ [sinπω ω ω ω/ / / ... sin sin sin ]

where ω  2 πf , the angular frequency.

32 100

160

140

120

100

80

60

40

20

320

Frequency

(d)

1 kHz 3.2 kHz 10 kHz

Group delay (

μs)

Figure 15.11(d) : The corresponding group delay curve shows a system that reaches a peak

delay of around 16 μ s.