... provide useful cues to assess the distance of a sound source. Previous studies in birds have shown that birds employ the degree of degradation of a signal to estimate the distance of another singing male (referred to as ranging). Little is known about how acoustic masking by background noise interferes...

... designs avoid both sources of ranging error, but only for a limited range of distances [the `distance of focus' (DOF)]. Here, we show that whiskered bats ( Myotis mystacinus ) using broadband echolocation calls adjust call design in a range-dependent manner so that nearby obstacles are localised...