I can safely say I'be never heard of "telephone shower". Sounds like a terrible electrocution risk, if you ask me.

Seriously ... you must mean those detachable shower heads connected by a flexible hose, right? I've seen this occasionally in US hotels, but not very often, and usually not in peoples homes. It does seem more like a European thing. Not having run into these very much, I haven't investigated some their stimulating possibilities ...