'Talking Whistle', one of a pair with M14.3.61/4. These end-blown flutes are 'notched flutes'; they are held vertically, and the player's breath is directed against top edge of the flute which is cut in a U-shaped notch.
The term 'notch flute' refers to the U-shaped cut at the top of the instrument. They are held vertically, and the player's breath is directed against the lower edge of the notch. This pair of flutes is associated with the Igbo speaking peoples of Nigeria. Igbo is a tonal language, meaning that different pitches can give words different significance. The flutes are probably intended to imitate the pitches used when speaking the language.