Learning about sound through inquiry in a semi-authentic environment with marine mammals

The subject "sound" is a compulsory part of the first year of physics curriculum in the Danish high school. The aim of the project is twofold: (1) to design a unit around an one-day session in a semi-authentic environment in order for students to obtain a rich understanding of the phenomena and (2) to reveal how the students’ understanding of sound is affected by their first-hand experience with the animals and with recording different animal and human made sound. The test of the unit was held at the Fjord & Bælt centre which is a marine biology exhibition in Denmark with 3 Harbour porpoises (Phocoena phocoena), 5 harbour seals (Phoca vitulina) and several fish species. www.fjord-baelt.dk.

The unit consists of 3 phases.

1. Before visiting the Fjord & Bælt centre: The class has received material about what kind of mini-projects they can do at the centre. The students choose a mini-project, read the recommended background material and formulate, in dialogue with their teacher, a problem for inquiry through the rest of the programme.
2. At the centre: After an introduction to the equipment where the students record their own voice, the students work with their mini-project for 40 minutes, recording for instance sound from the Harbour porpoises or observe the behaviour of the seals. All the students also get to make their own hydrophone. The rest of the day proceeds in class and covers through interactive teacher-student activities: The theory of sound propagation, wavelength and sound pressure, and interaction with devices where the students can see and feel sound waves. Before the students leave the centre they are given an introduction to a special designed version of the computer programme LabVIEW and the free sound programme Audacity.
3. After the visit: The students make further analysis of their data and studies and produce a poster to present their results from the mini-project. Students will be required to relate their own results to the other group’s mini-projects.

The design of the programme is based on "Theory of Didactical Situations" (TDS) (Brousseau 1997), which originates in didactics of mathematics and has been modified to this setting in physics and biology. The idea behind TDS is that teaching means designing a game where the winning strategy for the student is inquiring the outcome goals.
The programme was tested on 2 high school classes in May 2006. Before the students attend they were given a test of their preliminary conceptions and understanding of sound in general and sound production in marine mammals. The students were video recorded during the programme and after the programme the students was tested again, and focus groups were interviewed. The preliminary results of this study show that being in an environment working with marine mammals made the students interested in and able to relate to the subject sound. Hands on experience with sound recordings, analyzing data, seeing and feeling sound waves and making homemade hydrophones also helped the students to contextualize the phenomena sound.

Brousseau, G (1997): Theory of Didactical Situations in Mathematics 1970-1990 . Translated and edited by N. Balacheff, M. Cooper, R Sutherland and V Warfield). Dordrecht: Kluwer.