The wood-block or "log drum" (or "slit drum") is a parallelepipedic or cylindrical hollow wood instrument with an opening of African origin. The African log drums are originally portions of tree trunk lying on the ground, hollowed lengthwise, and beaten by thick sticks. Very loud, they were used to transmit important messages from village to village, through rhythmic codes (a bit like the "morse").Blast-block (yellow), jam-block (red) and woodblock (ebony)
More modern versions are plastic (PVC, nylon, bakelite, resin, etc.) to produce all sorts of dry, dull and tuned sounds.
They are often used in salsa by the timbalero or a drummer, to mimic the clave with a stick or beater, or embellish the solos, with unexpected sounds.
Marc De Douvan, November 2005, translation in English: May 2013.