Sony MDR-NC500D - Manual (Page 8)

8 GB
2.3. Advantages of Digitization
The performance of noise canceling headphones greatly depends on the efficiency of the
filter circuit (NC filter) between the microphone to detect noise and the driver unit to
reproduce the canceling signal.
In MDR-NC500D, the filter circuit for noise canceling is realized on the DSP as the
digital signal processing of the newly developed “DNC software engine.”
In addition to general advantages such as accurate computation results, no theatrical
variation, and no electric noise, the digital signal processing has also the advantage of making
it possible to create special filter shapes, which were not able to be realized with existing
analog filters.
During the development of the DNC software engine, the architecture of internal filter
computation was thoroughly examined in order to implement a more effective noise canceling.
The know-how of Sony’s digital sound treatment was used to construct a software engine
specialized in the noise canceling treatment and the calculation accuracy was heightened.
Noise canceling with less residual noise and higher Signal to Noise ratio was made possible.
Example of the characteristic of
conventional NC filter
Response
Frequency
Example of the characteristic of
digital NC filter
Response
Frequency