Many people have contributed in various ways to this study, I am particularly grateful to:

Mats Amundin, my supervisor, for his support and especially for his crazy idea of an “elephant telephone”; Bengt Sjölén, who provided the technical solution and developed the software for the acoustic link; Richard Kirkden, for his help with the underlying theory and for his valuable comments on the manuscript; Olaf Behlert, curator of the Cologne elephant house, and the Cologne elephant keepers for their willingness to participate in this project; Meike Artelt, for letting me use her recorded elephant rumbles; Mary Holmgren, for her help with the experimental set-up; Ulf Pettersson and Per Cedergren, for their help with the internet connection; Matthias Laska, for his help with German translation and Erik Häggmark, for his technical assistance and invaluable support!

I would also like to thank Nautilius Gym, for donating the weight lifting machines, BRL Electronics, for providing the microphones and speakers and Nordisk Mobiltelefon for providing mobile internet service.

Last , but not least, I would like to send the warmest thanks to the Kolmården elephant keepers Thomas Antmar, Andreas Levestam, Emelie Olander and Dan Köhl, for all their assistance and patience during this project!