Инструкция для Sony MDR-NC500D

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.