This work presents the development and experimental validation of a ionacoustic detector that uses a multi-channel sensor, a dedicated ASIC in 28nm CMOS and hardware DSP to reduce the input-referred noise power by 1-2 orders of magnitude compared to state of the art ionacoustic detectors. The most interesting application of the ionacoustic technique is the real-time monitoring with sub-millimeter precision of hadron therapy treatments, but the main limitation of current detectors lies in their high latency and noise power, not compatible with clinical treatments. The hereby presented High-Resolution Proton Sound Detector exploits the parallel acquisition and processing of 64 channels to obtain a 2D acoustic image of the source with 256x256 pixel resolution, 140 fps and 70 mPaRMS input-referred noise, resulting in 34 dB SNR with 0.8 Gy dose deposition.