Correct spelling for the English word "ponograph" is [pˈɒnəɡɹˌaf], [pˈɒnəɡɹˌaf], [p_ˈɒ_n_ə_ɡ_ɹ_ˌa_f] (IPA phonetic alphabet).
An instrument for recording graphically the progressive fatigue of a contracting muscle.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The closest word to "ponograph" that I am familiar with is "phonograph". The word "phonograph" has its roots in Greek. It combines two Greek words: "phono" meaning "sound" and "graph" meaning "writing" or "draw". "Phonograph" refers to a device invented by Thomas Edison in the late 19th century that could record and reproduce sound.