Which traditional African instrument is a type of gourd and shell megaphone?

The shekere is a traditional African instrument made from a gourd or a similar shell that is covered with a network of beads or strings. It is often used in African music to create a distinct percussive sound. The design of the shekere allows it to amplify sound, functioning similarly to a megaphone. When the gourd is struck or shaken, it produces rhythmic sounds that are integral to many African music traditions, serving not only musical purposes but also cultural and ceremonial ones.

In contrast, other instruments like the kalimba (a thumb piano), xylophone (a series of wooden bars struck with mallets), and ngoma (a type of drum), do not share the unique characteristics of being a megaphonic gourd instrument. Each of these has its own distinct role and construction in the realm of African music but does not fulfill the specific definition given in the question regarding the gourd and shell aspect.