African Burkina Faso Gurunsi Tribal Hunters flutes?

I bought these from my favorite thrift not knowing what they were, but they looked so interesting and at only $6 USD for the pair I had to have them. They are 8 1/2" and 5 1/2" long
Google images tell me what they are, but not how they work or how old they might be.
Thanks for any additional information.
Mikey

 

https://wmic.net/mossi-bulbous-hunters-flute-a/

Are yours hollow, with an opening at the top of the large end?

 

Yes they are hollow. One end has a larger opening.
Two other small holes on th ed sides.
Mikey