Active noise cancelling
Active noise control (ANC), active noise cancelling, and active noise reduction (ANR) are names of method where an unwanted sound is reduced by adding another sound specifically made to cancel it out.
QuietOn with Active Noise Cancelling technology makes a big difference at low frequencies, such as the hum of airplane engines, construction sites or normal background noise. Its attenuation ability in this area is up to 40dB. For instance, airplane cabin noise sounds like a faint hum with QuietOn earplugs. The earplugs significantly reduce stress level caused by constantly noisy environments. In mid and high frequencies, QuietOn’s noise cancelling is as good as foam earplugs’.
How it works
Active noise cancelling uses a microphone to sample the sound, and a speaker to create a phase-shifted sound that cancels the original sound.
In QuietOn, the microphone that samples the sound is located right inside the ear canal! This means that QuietOn can more accurately produce anti-noise that results in good noise cancellation at the ear drum. By locating the microphone in the air volume of the ear canal, QuietOn is also able to reduce noise that is conducted by the skull into the ear.
Do you know about
sound frequencies & decibels
The frequency of a sound is characterized as a periodic vibration of air pressure. It is measured as vibrations per second, and it’s unit is hertz (Hz). Frequency is the property that determines pitch. It is generally accepted that a human can hear frequencies between 20 and 20,000 Hz, although the range of frequencies individuals hear is greatly influenced by age, hearing loss and the loudness of sound.
Sound pressure level (SPL) is a logarithmic measure of the pressure of a sound relative to reference of 20 micropascals which is the threshold of human hearing at 1000 Hz. This is defined as SPL of 0 dB. Every 10 dB increase in SPL is perceived roughly as doubling the loudness.