Acoustic characteristics of Ekonda scrapers
Didier Démolin, Stéphanie Weisser · The Journal of the Acoustical Society of America · 2002
This paper describes some acoustic characteristics of a musical instrument played with the complex vocal polyphonies of the Ekonda of the Congo. The complexity of these songs and the remarkable pitch accuracy of their intonation are striking given that there is no tuning fork or fixed pitch instrument which can account for the pitch stability. Ekonda scrapers are required to accompany the polyphonies. An acoustic study of these idiophones was made to understand their contributions to the songs. The scrapers are made in a hollow piece of a palm tree branch. The instrument is played by rubbing a piece of hard wood upon splits made on the piece of palm tree. In addition to the friction noise due to the rubbing of the piece of hard wood, there are some very distinct resonances which can be identified. An important observation is that there is always a very intense resonance at the frequency of the musical scales tonic. The relation between the pitch of the tonic and the frequency of the scrapers resonances which act as a tuning fork are detailed.