@Recc:
We developed the RATS to track the model V22P acoustic transmitter [...] which is specified to transmit a 36-kHz “ping” at 165 dB once every 700–1100 ms. The pulse duration of the ping is 10 ms
You forgot to mention that the 700-1100ms pulse interval isn't a tolerance, it's a range; the pulse interval is varied to encode the depth of the transmitter. The chance of it being precisely, and consistently, 1s is therefore remote, and readily distinguished from an aviation ULB.