Regardless of your taste in music, there’s one thing you wouldn’t want to hear – ambient noise. Fortunately, there’s a type of audio equipment that is particularly designed to improve your listening experience by keeping ambient noise at bay while preserving the quality of your music. We call them noise-canceling headphones. But how exactly do they work? Learn more about sound performance, go here.
To understand the mechanics behind noise-canceling headphones, you first need to understand headphones themselves. If you’re like most people, you probably automatically think of water whenever you hear the word, waves. A transverse wave is one that causes a disturbance in a medium that lies perpendicular to the path of the an advancing wave. A common example of a transverse wave is a shallow water wave.
Waves form moving crests, or the highest points a medium rises to, and moving troughs, which are the lowest points a medium dips to. In between any two crests or trows is a distance known as the wavelength, while the a crest’s height or a trough’s depth is known as the amplitude. Frequency is the number of crests or troughs passing a certain point for every second. Find out for further details on audio quality right here.
Sound waves have several characteristics shared in common with water waves, but they are longitudinal waves which are produced by a medium’s mechanical vibration, setting off a number of compressions and rarefactions in that medium. For example, plucking a guitar string will cause it to vibrate.
The string you have pulled will first press against air molecules, which serve as the medium, and then pull away. This creates an area in which all air molecules are compressed, and right next to it, another area where they are dispersed. While these compressions and rarefactions move from point to point, they create a longitudinal wave, where the disturbance of the medium moves along the wave’s direction.
Longitudinal waves have essentially the same qualities as transverse waves. A compression is to a crest while a rarefaction is to a trough. In between two compressions therefore is a wavelength, and the amount of compressed medium is the amplitude. Frequency is simply how many compressions pass a certain point from second to second.
Frequency dictates the pitch, with higher frequencies generating higher pitch notes and vice-versa. As we know, the brain is capable of discerning sound characteristics, but before that is possible, a sense organ must first detect the sound waves. Of course, we know that’s the ear. In noise-canceling headphones, a process known as Active Noise Cancellation (ANC) or Active Noise Reduction (ANR) simply removes unwanted ambient noise by adding a second sound that is particularly meant to neutralize the first.