Sony MDR-NC500D - Manual (Page 5)

5 GB
GB
2.
Principle of Operation of MDR-NC500D
and Its Configuration
The noise canceling headphones make a canceling signal by analyzing with their noise
canceling circuit the surrounding noise collected by the small noise detection microphone built
in their main body.
With this canceling signal superimposed on the regenerative signal from the connected
equipment, reproduction from the driver unit reduces surrounding noise and makes it possible
to listen to music more clearly.
For the noise canceling, the following two methods are mainly used:
• Feedback type
• Feedforward type
1. Waveform of noise
(original sound)
Surrounding noise is collected by
the noise detection microphone
built in the headphones and its
signal is analyzed with the noise
canceling circuit.
2. Inverted sound
waveform
The inverted sound, which can
negate the analyzed noise, is
generated.
3. Sound waveform
canceled by
superimposition
By overlaying the original sound
with the inverted sound, the
original sound is negated. This
reduces noise at the eardrum.
Continued