A wireless noise-cancelling earplug includes a housing within which at least an active noise cancellation (ANC) circuit for producing anti-noise, a speaker for emitting the anti-noise as a sound wave, and a battery for powering at least the ANC circuit. The earplug further includes an audio cavity for guiding the sound wave from the speaker out of the earplug, at least one microphone for measuring ambient noise and feeding the measured ambient noise to the ANC circuit, and a passive noise reduction unit for blocking ambient noise.
