Help with decoding Zoom ultrasound protocol

i haven't looked at this in a while, but off top of my head, 144000 sample(?) 16 bit 48khz 2channel, raised chunks are the ASCII int value of a (char)'LETTER' - (char)'0'. these raised chunks will be padded to a minimum length of some kind, probably 12 characters based on the waveform/spectrum. i think the later chars unused are ascii (char)'0' / (int)48 and stripped.

flat part at the front before the sequence is some kind of preamble that specifies whether it's in a meeting or waiting to start one. this is an 3 or 4 possible value int, iirc. the lowest value is before a meeting has started.

notes: (chr&0xFF) ((chr>>8)&0xFF) ((chr>>16)&0xFF) ((chr>>24)&0xFF)