US Patent 10897663 Active transit vehicle classification

A method performed by a wearable audio output device worn by a user is provided for controlling the reproduction of external noise and/or noise masking. A first a first lower-power detector determines if the user is in transport or a change in the user's transport. In response to the determination, a second higher-power detector exits a power saving state and determines a mode of the transport based. The wearable audio output device adjust a level of attenuation applied by the wearable audio output device to the external noise or adjusting a level of noise masking output by the wearable audio output device based on the determined mode of the transport.