Noise Cancelling vs Noise Isolating
Listening to music on an airplane or while commuting to work in public transport may be a challenging experience because of the annoying effect of the surrounding sounds. Noise cancelling headphones and noise isolating headphones are solutions to these situations, where the surrounding noise is prevented from affecting your listing experience.
Noise Isolating
Noise isolation is reducing the background noise by preventing the noise entering the ear canal. Noise isolating headphones are often earphones with sleeves designed to seal the ear canal completely when the earphone is put on. As a result, the background noise cannot pass a significant amount of sound to the eardrum to create the sensation. This method is known as passive noise reduction.
Noise Cancelling
Noise cancelling is reducing the ambient noise using active components in the earphone system. The fundamental behind this is to disturb or the attenuate the unwanted frequencies. A microphone detects the noise outside and passes that to a processing unit, and the processing unit creates a sound output that will interfere and cancel the unwanted frequencies. This method is known as active noise reduction. Some noise cancelling headphones employ both active and passive noise reduction.
The processing unit of the headphone can successfully cancel the low frequency noise, but high frequency noise requires more advanced circuitry and poses a problem in terms of power, performance, weight, and cost. Therefore, noise isolating techniques are also used to reduce the high frequency noise.
These noise cancelling headphones were spinoff products from the research for developing noise reduction headset for airplane cockpits. Today most of the military and commercial aircraft pilots use noise reduction headphones to obtain better hearing conditions in the cockpit. Properly designed headphones are capable of reducing the aircraft engine noise by up to 90%. Some of the commercial airlines offer noise cancelling headphones for their first and business class passengers.
Even though these headphones are able to reduce the noise significantly, there are inherent disadvantages. Since these headphones contain circuitry that actively participates in the process, a power source is needed and occasional recharging or replacing the batteries is compulsory. If the power source does not provide enough power, the unit might act as an ordinary headphone, or might not function at all.
The circuitry removes noise but also adds noise. These noise levels are insignificant when the surrounding noise level is high, but when the surroundings are quiet the noise is added to the music, especially in the form of high frequency “hiss”.
What is the difference between Noise Cancelling and Noise Isolating Headphones?
• Noise isolating headphones use passive noise reduction techniques (Have no active components contributing to noise reduction) while noise cancelling headphones use active noise reduction (have active circuitry) techniques or both.
• Noise isolating headphones prevent the noise entering the ear canal by sealing the ear canal with specially designed sleeves. Only the music can get through. In noise cancelling headphones, a sound wave is created by the processing unit, to interfere the noise destructively.
• Noise isolating headphones come as intra-aural headphones, which are commonly known as earbuds. Noise cancelling headphones comes as circumaural headphones, which are covering the whole ear.
• Noise cancelling headphones uses a power source, such as a battery and needs to be recharged or replaced occasionally. If the power source does not work, the unit does not function properly. Noise isolating headphones have no power sources.
• Noise cancelling headphones are larger than the noise isolating headphones.
• Relatively, noise cancelling headphones are expensive than the noise isolating headphones.