Interface device i.e. hands-free adapter, for relaying audio signals from audio signal source e.g. wireless telephone, has CPU activating functionality and alarm, if presence of signal is detected and not detected, respectively

摘要

The device i.e. hands-free adapter (10), has an initiation unit initiating a predetermined functionality e.g. calling, by a user. A generating unit produces a reference signal e.g. musical signal, and an analyzing unit executes a signal detection algorithm in a noisy environment to recognize the presence of the reference signal in sound signals captured by a microphone (20). A CPU activates the functionality if the presence of the reference signal is detected, and inhibits the functionality and activates a video and/or sound alarm for the user, if the presence of the signal is not detected.