Agilent Technologies PSA Series Manual page 303

Audio Distortion Measurement Concepts
Purpose
Audio Distortion measures the amount of Audio distortion contained in the Audio
signal by determining the ratio of harmonic and noise power to fundamental
power.
Measurement Technique
Audio Distortion is defined as:
Equation 5-5
where: P
P
P
noise.
See Figure 5-12 on page
DC, then the filtered audio signal is transformed by an FFT into frequency domain.
Next, total power in the total filter band is measured as P
wanted signal is computed as P
P
total
dB or %.
Chapter 5
P
total
% = ---------------------------------- -
AudioDistortion
= the power of the total signal,
total
= the power of the wanted audio signal, and
signal
− P
= total unwanted signal which includes harmonic distortion and
total signal
302. First, the received Audio signal is filtered to remove
signal
is calculated. The result is signal's Audio Distortion. It can be expressed as
Audio Measurement Concepts
– P
signal ×
100%
P
total
, the peak power of
total
, the square root of the ratio of P
Concepts
− P
to
total signal
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