An acoustic transducer and audio system are checked for operability continuously during operation without interfering with their operation. An inaudible test signal is added on top of a normal audio signal of an electronic device. A mix of the test signal and the normal audio signal is converted to a digital signal which is processed by a type of Fourier transformation, e.g. the Goertzel algorithm, to derive the magnitude of the digital signal at the test signal frequency. The derived magnitude is used to gain knowledge about the functionality of the acoustic transducer and its electrical connection to the electric device, as well as a common audio path.