CPC G10L 17/26 (2013.01) [G01S 7/52004 (2013.01); G01S 7/539 (2013.01); G01S 15/58 (2013.01); G01S 15/88 (2013.01); G10L 17/00 (2013.01); G10L 25/51 (2013.01); G10L 25/03 (2013.01); H04W 88/02 (2013.01)] | 13 Claims |
12. A system for liveness detection in a device, the system comprising:
at least one microphone input, for receiving an audio signal from a microphone; and
at least one transducer output, for transmitting a signal to an ultrasound, and the system being configured for:
receiving a speech signal from the at least one microphone input;
generating a control signal through the transducer output, for transmitting an ultrasound signal through a transducer of the device;
detecting a reflection of the transmitted ultrasound signal;
detecting Doppler shifts in the reflection of the generated ultrasound signal; and
identifying whether the received speech signal is indicative of liveness of a speaker based on the detected Doppler shifts,
and the method further comprising:
obtaining information about a position of the device relative to the voice source; and
adjusting the transmit power of the ultrasound signal based on the information about the position of the device relative to the voice source;
wherein adjusting the transmit power comprises increasing the transmit power when the device is moved further away from the voice source.
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