This is the sound of Tuuli’s piano, which is kept in her parents’ place in Võru, in the same room as her loom.
You can hear the two devices together; the loom and the piano, both of them with their strings being beaten. On the piano, the strings are struck by a hammer and on Tuuli’s loom, the warp strings are struck by the beater. Felicity is playing the Piano in the first clip, and Tuuli is teaching Felicity how to weave a rug in the second clip.