An apparatus and as method for generating ultrasound. The apparatus comprises: a signal generator arranged to generate a driving signal； and an ultrasound transducer arranged to transmit an ultrasound beam in response to the driving signal received from the signal generator. The signal generator is arranged to combine a carrier wave and a modulating wave having a lower frequency than the carrier wave to generate an amplitude modulated driving signal. The ultrasound beam is suitable for inducing cavitation in a human or animal body tissue.
