I am making a digital sound mixer and get this wav file (200kb, Wetransfer)
I looked through the waveform using Audacity. It uses 20% of its maximum amplitude and I see no sudden changes in the waveform.
Yet it repeatedly clicks.
It is composed (not maxed) sine waves, first 1, later 4. But the waveform looks like I avoided constructive interference (by reducing volume).
Interestingly when combined with other sounds (music, ambience), the clicking is almost removed.