Sound wave processing device and ultrasonic system

A sound wave processing device comprising:

• a driving unit that outputs a burst drive signal so as to drive a sensor element for transmitting a sound wave;
• a received wave signal output unit that outputs a received wave signal based on a received sound wave;
• a band pass filter to which the received wave signal is input;
• and
• an own wave determination unit that determines whether or not the received sound wave is a reflected wave based on a sound wave transmitted from own ultrasonic system including the sound wave processing device, on the basis of an output of the band pass filter, wherein
• in one session of transmission, the burst drive signal has a sensor drive period for transmitting a first drive signal, and an interval period disposed between the adjacent sensor drive periods of the burst drive signal, for transmitting a second drive signal,
• the first drive signal has a frequency within a frequency band of the band pass filter, and
• the second drive signal has a frequency that is different from a resonant frequency of the sensor element and is outside the frequency band of the band pass filter,
• wherein the second drive signal has a frequency higher than the frequency band of the band pass filter.