The First Portable System for Measuring Hearing Damage in Whales, Dolphins and Porpoises

The Laboratory of Applied Bioacoustics at the Polytechnic University of Catalonia, Spain, managed by researcher Michel André, has developed the first portable system in the world for measuring the hearing sensitivity of cetaceans.

The audiographic measuring system makes it possible to make in situ diagnoses of possible hearing loss in cetaceans (whales, dolphins and porpoises). In the case of beached animals, it is able to determine their chances of survival without having to be taken to a laboratory. Researchers from Spain, the United Kingdom, France, the Netherlands and the United States were involved in the project, which was conducted thanks to the support given by the Fundación BBVA, a Spanish foundation that specializes in promoting scientific research in the area of social science, biomedicine and the environment.

Cetaceans are the most threatened species in the world, due, amongst other things, to problems directly caused by human sources of sound. This can lead to collisions with ships and the mass beaching of animals after military maneuvers.

Although there is no conclusive data of the impact of noise pollution on the disorientation and death of these animals, it has been widely accepted that the negative effects of noise have irreversible repercussions on their sense of hearing.

The purpose of this project is to carry out research into how noise from human activities affects cetacean populations and the marine environment in general. The results of the research will enable the team to develop and apply specific solutions that monitor human activity so that a balance can be achieved between human development and the conservation of marine mammals.

The only practicable system to date for measuring the hearing sensitivity of cetaceans was to take them to a laboratory. However, given the size of these animals and their precarious state of health when they are beached, this was a complex procedure and posed considerable risks to their survival. This project has made it possible to develop the first portable system for measuring the hearing sensitivity of cetaceans in situ. Thus, a diagnosis can be made of their loss of hearing, and in the case of beached animals, an assessment made of their chances of survival without having to move them.

The propagation of biological acoustic signals involved in echolocation is also a subject for study in the framework of this project. Special emphasis is placed on how animals detect their prey in noisy environments. The Laboratory of Applied Bioacoustics on the Vilanova i la Geltrú Campus in the Barcelona province of Spain is also working towards the goals of the project and is putting the final touches to a system that involves preventing the collision of cetaceans with fishing nets.

Source: La Universitat Politècnica de Catalunya (UPC)