Apparently you did not understand the fundamental difference of idea of a pulsating metronome - it does not act on hearing, but on the body. Rhythm problems can be associated with cerebral insufficiency, for example, dyscalculia; where an ordinary metronome is completely helpless. In such cases, the rhythmic touch on playing hand restores the pupil's sense of rhythm. Until now, I used melodica for this, but such a metronome can solve the problem right away on the instrument.Most keyboard workstations have a click / sequencer these days. Used ones are so inexpensive it's crazy... Run it through your amp combo / stereo / PA / studio / whatever and it'll be as loud as your gear allows...and you get a new toy to play with that does more than go "click"