Sony MDR-NC500D User Manual

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HOW DO THEY WORK? 
MDR-NC500D Digital Noise Canceling Headphones 
 
To create the noise-reducing technology in the MDR-NC500D, Sony used digital technology with Artificial Intelligence. 
Cool, huh? Together with its acoustical analysis and transducer technologies, the result is improved noise cancellation 
performance and excellent sound quality, with rich bass and crisp mid and high range frequencies.  
 
The increased rate and accuracy of noise reduction in these six-ounce headphones is due to the use of a unique digital 
noise canceling software engine – a set of digital filters located in the built-in digital signal processor. Here’s how it works. 
 
 
 
1.  To start the digital noise canceling (DNC) process, a microphone found inside the ear 
cup of the headphones takes an analog audio reading of the ambient noise and 
converts the sound to digital.  
 
2.  At the same time, the analog audio input signal from the audio source (like a Music 
player) is converted to a digital signal. Then it’s sent through a digital equalizer to 
enhance the mid-range vocals and alleviate the excess bass – two sound elements 
that can be negatively affected in most noise-canceling headphones. 
 
3.  The audio source signal is compared to the ambient noise signal, and the DNC 
software engine uses a digital filter to remove ambient noise that registers in the 
desired frequency range.  
 
4.  The resulting signal is converted back to analog and sent to the headphones’ driver 
for sound reproduction and sent to the listener’s ear.   
 
This digital-based process enables more effective noise cancellation than is possible using analog filter technology. Sony’s 
DNC software engine makes it possible for these digital noise canceling headphones to offer three distinct noise canceling 
modes optimized for different environments: airplane, train/bus or office