The lounuet is a wooden block used as a friction instrument in New-Irland.
It mimicks birds or frogs and was used in ceremonial as well as in everyday performances.
The three plates are rubbed which produces a pitched or a rough sound.
The instrument is astonishingly loud. This is due to the resonance chambers below the plates. Naively one might suggest that each chamber resonantes with the frequency of the plate above it. Still the pitches are too high to resonate in such small chambers. Indeed the resonance is an interaction between different chambers. This makes the craftsmanship of the lounuet complex, as the chambers need to be carved in such a way that all three plates resonate. Otherwise the instrument is very low in volume, which is the case with tourist instruments not carved by experts.
Using a microphone array the radiation of the plates can be measured. Below are the radiations for all three plates, once rubbed, once knocked on. In all cases a phase / anti-phase relation between neighbouring chambers lead to the overall radiation of the instrument.