Noise Canceling Headphone-NW-001 Key Specifications/Features:
Noise-canceling Headphone, wide range Frequency response, battery
embedded, high sensitivity
|Noise canceling||23dB at 300Hz|
|Operating time||50 hours|
What's Noise-canceling Headphones?
Noise-cancelling headphones are headphones that reduce unwanted
ambient sounds using active noise control. This is distinct from
passive headphones which, if they reduce ambient sounds at all, use
techniques such as soundproofing.
Noise cancellation makes it possible to listen to music without
raising the volume excessively. It can also help a passenger sleep
in a noisy vehicle such as an airliner. In the aviation
environment, noise-cancelling headphones increase the
signal-to-noise ratio significantly more than passive noise
attenuating headphones or no headphones, making hearing important
information such as safety announcements easier. Noise-cancelling
headphones can improve listening enough to completely offset the
effect of a distracting concurrent activity.
To cancel the lower-frequency portions of the noise,
noise-cancelling headphones use active noise control. They
incorporate a microphone that measures ambient sound, generate a
waveform that is the exact negative of the ambient sound, and mix
it with any audio signal the listener desires.
Most noise-cancelling headsets in the consumer market generate the
noise-cancelling waveform in real-time with analogue technology. In
contrast, other active noise and vibration control products use
soft real-time digital processing.
To prevent higher-frequency noise from reaching the ear, most
noise-cancelling headphones depend on soundproofing.
Higher-frequency sound has a shorter wavelength, and cancelling
this sound would require locating devices to detect and counteract
it closer to the listener's eardrum than is currently technically
feasible, or would require digital algorithms that would complicate
the headphone's electronics.
Noise-cancelling headphones specify the amount of noise they can
cancel in terms of decibels. This number may be useful to compare
products, but does not tell the whole story, as it does not specify
noise reduction at various frequencies.
Noise-cancelling headphones have the following drawbacks:
a) They typically cost more than regular headphones.
b) Active noise control requires power, usually supplied by a USB
port or a battery that must occasionally be replaced or recharged.
Without power, some models do not even function as regular
c) Any battery and additional electronics may increase the size and
weight of the headphones compared to regular headphones.
d) The noise-cancelling circuitry may reduce audio quality and add
high-frequency hiss, though reducing the noise may result in higher
perceived audio quality.