Sikarian atmospheric sensor

From Memory Alpha, the free Star Trek reference

The Sikarian atmospheric sensor was a device found on the planet Sikaris.

It emanated sounds and also looked like a musical instrument, but it wasn't one, as the frequencies of the chimes it emanated indicated changes in the weather conditions of Sikaris.

The Eudana showed Harry Kim of the USS Voyager how to use the atmospheric sensor. (VOY: "Prime Factors")