I would not expect finding such a list. Especially in german there are a lot of "Lautmalereien". One pair that comes to my mind is e.g. "klingeln"-"to ring".

Ich habe etwas gefunden: Es sind zwar nur Tierlaute, dafür in 28 Sprachen(!).

http://www.georgetown.edu/faculty/ballc/anima...

Hat das Wort "onomatopoeia" eigentlich eine Pluralform?

It seems like onomatopoeia denotes an "un-pluralized matter"(!)
such as sand, water, earth, air, media, data (in modern english) etc..
Otherwise, you might go back to the old greek grammar to find pluralis conjugations...

Julie:

Laut WIII: -s

Many Thanks