SIGNAL PROCESSING DEVICE, ACOUSTIC WAVE SYSTEM, AND VEHICLE

The invention relates to a signal processing device, a sound wave system and a vehicle. The present disclosure provides a signal processing device capable of detecting an object located at a close distance. A signal processing device according to the present disclosure is provided with: an acoustic wave transmission signal generation unit configured so as to generate an acoustic wave transmission signal for transmitting an acoustic wave; an acoustic wave reception signal output unit configured to output an acoustic wave reception signal based on the received acoustic wave; and a reflected wave sensing unit. The reflected wave sensing unit is configured so as to sense a reflected wave on the basis of a signal obtained by envelope detection of an absolute value of the acoustic wave reception signal during a reverberation period in which reverberation remains in the acoustic wave transmission, i.e., a first time at which a so-called envelope detection signal is lower than a first threshold value, and a second ti