Praise be to Allah.
We put this question to Shaykh ‘Abd-Allaah ibn Jibreen (may Allaah preserve him) who answered as follows:
In our opinion it is haraam because it sounds like, and could be taking the place of, musical instruments, which are forbidden and which distract people from remembering Allaah. So whatever takes their place is also haraam. And Allaah knows best.