Sweep is a grey glove puppet dog with long black ears who joined The Sooty Show in 1957, as a friend to fellow puppet Sooty.
[2][3] Sweep is notable for his method of communication[4] which consists of a loud high-pitched squeak that gains its inflection from normal speech and its rhythm from the syllables in each word.
The rest of the cast, namely Soo and the presenter, could understand Sweep perfectly, and would (albeit indirectly) translate for the viewer.
[5][6] The sound of Sweep's voice was achieved using "something similar to a saxophone reed".
[7] Versions of the puppet later sold as toys had an integral squeaker connected to an air bulb that was squeezed by hand.