Rhinolophus uses long constant-frequency calls emitted through the nostrils, with the noseleaf acting as an acoustic lens to focus the beam. The cochlea contains an over-represented region, the acoustic fovea, tuned to a narrow band of frequencies near the species-typical call.
The problem is Doppler shift. A bat closing on a target hears its own echo return at a higher frequency, which would push it outside that tuned band. Horseshoe bats solve it by lowering the emitted frequency in proportion to their flight speed, so the returning echo lands where the ear works best. The behaviour was described by Hans-Ulrich Schnitzler in the 1960s and is called Doppler shift compensation.
What this buys is not distance so much as texture. Beating insect wings modulate the returning constant-frequency tone, producing acoustic glints that let a horseshoe bat detect a fluttering moth against dense foliage, where a broadband clicking bat would be swamped by clutter echoes.