A head-worn audio device is provided with a circuit for voice signal enhancement. The circuit comprises at least a plurality of microphones, arranged at predefined positions, where each microphone provides a microphone signal. The circuit further comprises a directivity pre-processor and a blind source separation processor. The directivity pre-processor is connected with the plurality of microphones to receive the microphone signals and being configured to provide at least a voice signal and a noise signal. Directivity pre-processing increases the mutual independence of the signals provided to the blind source separation processor and thus improves processing by blind source separation. The blind source separation processor receives at least the voice signal and the noise signal, and is configured to conduct blind source separation on at least the voice signal and the noise signal to provide at least an enhanced voice signal with reduced noise components.