Bird Technologies SH-36S-RM-Manual - Manual (Page 77)

Measurements
61
Received Signal Strength Indicator (RSSI)
RSSI provides an audible indication at the frequency of the current
marker. It will beep faster as the received signal strength goes up and
slows as it goes down.
Similar to Water Fall, power is linearly mapped to a range of 0-210
using the same range as for the Water Fall for simplicity. The beep
rate and volume are proportional to the mapped power value at the
current marker index. Values of zero are equivalent to continuous
beeps and -210 are equivalent to a beep every 4 seconds.
Figure 46 Example, Field Signal Strength - RSSI