Sounds like a power on sound. Made from a beep with a sine waveform (the hz of which increases), and bitcrushing it at 4 bits per sample and a sample rate of 40khz.
Nine raw and dirty samples of my lovely hokema sansula. Probably used the rode nt5 microphone. Recorded in an untreated room. . Captured straight into ni's maschine. Enjoy!!! ;-).