By Kapil Gulati
Over the years there have been a handful of products designed to model headphones. The devices used to translate these formats into sounds that we can enjoy on a daily basis have also transformed. Looking at technology growth with too narrow a time frame obscures the long-term trend. The apparatus hasn’t really changed, but the technology that goes into them are in a constant state of development.
Outside disturbances like the roar of a jet, the clamour of a commuter rail and the murmur of an open office can conspire to keep you from concentrating. This is where noise cancellation headphones come into play. Noise-cancelling headphones, long the refuge of pilots and road warriors, have become so convenient they are worth a look for ordinary commuters and cubicle-dwellers, too. Normal headphones just cover your ears and try to out-blast everything else. Noise-cancelling ones use microphones and software to actively delete sound before it reaches your ears.
How do noise cancelling headphones work?
Noise cancelling headphones reduce unwanted ambient sounds using active noise control. They make it possible to listen to music without raising the volume excessively. It can also help a passenger sleep in a noisy vehicle like 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.
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.
There is a lot of competition in the market prevailing for noise-cancellation headphones. A few technological leaps have improved the current generation of noise-cancelling headphones. They no longer require throwaway AA batteries: Now you charge them like a phone, and they can run for up to 20 hours at a time. Without the extra noise, users can enjoy the sound of silence. In many situations without the noise cancelling feature, pumping up the volume is the only wise option. This can be dangerous, especially during traveling on planes or in surroundings where disturbing noises are prevalent, and increasing the volume will, in most probability, become excessive. Apart from being dangerous, it also defoliates the sound quality.
With awareness in the market, they have become an important part of your carry bag while travelling. Long-haul battery performance and advancement in technology, provide for a recommended pair of these headphones for travellers seeking the ultimate experience. Apart from travelling they are used for aviation purposes to block any outside disturbances.
Using these headsets, a student can study in a room next to a loud roommate, a passenger in a plane can continue working on an assignment, or a person trying to relax at a subway station enjoying a crossword puzzle can do so with fewer disturbances. With the distractions pushed aside, noise cancelling ear pieces allow users to focus on their stuff without interruption, making them more productive, or if their just kicking back, they can have a more enjoyable downtime.
One of the main drawbacks of noise-cancellation headphones are that they are slightly more expensive than your usual headphones. Hence, while considering a good set of headphones, it is very important to take in account a lot of aspects like good battery life, design, comfort, among others. An ideal set would be such which has upto 30 hours of battery life, 4-microphone noise cancellation system and can automatically pause music and calls when the headphones are taken off. It should combine supreme ease of use with features that discretely anticipate the needs of the user, ear cup-mounted touch control panel and voice prompt system which allows for a convenient selection of settings.
Kapil Gulati is the director, Sennheiser India’s Consumer Segment.