· General introduction:
history of bioacoustic research, sound characteristics, infra- and ultrasound, sound recording and analysis, practical use of bioacoustics

· Vocal communication:
general patterns of communication, costs and benefits of acoustic communication, conventional vocal signalling

· Communication networks and motivation-structural rules:
eavesdropping, audience effect, etc. in communication networks; interspecific vocal communication

· Variability in intraspecific vocalisation I:
geographic variation

· Variability in intraspecific vocalisation II:
Temporal variation; Song and territoriality, duetting; Individual recognition

· Vocal communication in poor visibility:
Ultrasound and underwater vocal communication