Audiogram of Humboldt penguins

So far it is only known for few penguin species which frequency range their sense of hearing covers - this means it is unknown which sounds of which amplitude they are just able to detect. This makes it impossible to accurately measure the influence of anthropogenic noise in their habitats on the different populations and species.

The goal of this project was to unravel in which frequency range Humboldt penguins can perceive sound underwater with the aim to generate a full audiogram. Therefore, the animals were being conditioned to respond to a perceived sound under water in a psychophysical experiment.