Short-term adjustments of signal characteristics allow animals to maintain reliable communication in noise. Noise-dependent vocal plasticity often involves simultaneous changes in multiple parameters. Here, we quantified for the first time the relative contributions of signal amplitude, duration, and redundancy for improving signal detectability in noise. To this end, we used a combination of behavioural experiments on pale spear-nosed bats (Phyllostomus discolor) and signal detection models. In response to increasing noise levels, all bats raised the amplitude of their echolocation calls by 1.8–7.9 dB (the Lombard effect). Bats also increased signal duration by 13%–85%, corresponding to an increase in detectability of 1.0–5.3 dB. Finally, in some noise conditions, bats increased signal redundancy by producing more call groups. Assuming optimal cognitive integration, this could result in a further detectability improvement by up to 4 dB. Our data show that while the main improvement in signal detectability was due to the Lombard effect, increasing signal duration and redundancy can also contribute markedly to improving signal detectability. Overall, our findings demonstrate that the observed adjustments of signal parameters in noise are matched to how these parameters are processed in the receiver’s sensory system, thereby facilitating signal transmission in fluctuating environments.
You may also like
Getting in the Groove: Why samba makes everyone want...
Estimating the pace of change
April 26, 2022Max Planck Institute for Biological Cybernetics
Out of rhythm: Compromised precision of theta-gamma...
April 26, 2022Max Planck Institute for Human Development
Near-natural, fractal architecture promotes well-being
April 26, 2022Max Planck Institute for Biological Cybernetics
Decoding cognition from spontaneous neural activity
April 26, 2022Max Planck Institute for Human Development
What and Where: Location-Dependent Feature Sensitivity...
April 13, 2022Max Planck Florida Institute for Neuroscience