"产生单音调的" can be translated as "producing a single tone" or "generating a monophonic sound" in English. The choice between these phrases may depend on the specific context in which it is used.
"Producing a single tone" is more straightforward and commonly used when referring to the creation of a solitary, unchanging musical note or sound.
"Generating a monophonic sound" is more technical and might be used in audio engineering, music production, or scientific contexts where the focus is on the sound's properties rather than its musical application.