Male crickets and katydids produce loud acoustic signals or calling songs to attract conspecific females from a distance. These signals contain information on species identity, mate location and quality, opening up the possibility of female choice based on acoustic signals. Using a tree cricket species, male signalling and female choice were examined from a sensory ecological perspective. Females preferred larger and louder males. An interesting alternative signalling strategy used by males of this species is to build acoustic amplifiers using leaves that increase call loudness: this is shown to be a condition-dependent strategy used by disadvantaged males. Finally, the costs of acoustic signalling by males and searching by females are examined and contrasted in two predator-prey systems: tree crickets and their spider predators, and katydids eaten by predatory bats.