From Wikipedia
Timbrh is an instrument belonging in lamellophone class, traditional to the Mambila people of Cameroon. The wooden base are generally made of thin woods or hollow raffia palm stems. The lamellas of timbrh, which can be in numbers up to 20, consists of hard leaf veins of raffia palms. It also features a triangular soundholes. In a typical dance accompaniment ensemble, three to four timbrh play together. A variant with a smaller box is only used as a solo. In an older, now obsolete version of the timbrh, the lamellae were attached to two parallel connected raffia leaf ribs cut in half.