We made considerable improvements in Bose Sleepbuds™ II: Cancellation creates quiet in our ear canals masking - in the right conditions - creates quiet in our minds. Masking works because of the way different sounds combine in our inner ears if they have the right match of frequencies and the masking sound is just enough louder than the disturbing sound, the inner ear and brain cannot detect the disturbing sound. Masking, on the other hand, introduces a soothing, desirable sound to help the brain ignore the disturbance. However, no combination of passive and active technologies for reducing the sound entering a user’s ear can make unwanted noises completely inaudible. In Bose Acoustic Noise Cancelling™ products, noise cancellation is combined with passive blocking to achieve a good reduction of sound at all frequencies.

Noise cancelling technology continuously measures, compares, and reacts to outside noise, then cancels it with the opposite signal. Although Bose pioneered noise cancelling technology, we found that masking is better for addressing noises that disturb sleep.

Soft morning alarm tone