Multisensory integration facilitates perceptual restoration of an interrupted call in frog

How to render an interrupted sound as a complete signal is a common challenge faced by human and non-human animals during vocal communication. Using video and audio playbacks, we showed that neither inserting white noise into the silent gap of an interrupted call nor displaying the dynamic inflating-deflating vocal sac in that same gap restored attraction of the call equivalent to that of a complete call. Simultaneously presenting a dynamic vocal sac along with white noise in the gap, however, rescued the interrupted call making it as attractive as a complete call. This suggests that the multisensory cue might have caused female frogs to “hear” the missing sound as happens when humans experience auditory induction. Regardless, such novel multisensory integration suggests that multimodal signals can provide insurance against imperfect sender coding in a noisy environment, and the communication benefits to the receiver from multisensory integration may be an important selective force favoring multimodal signal evolution.