The trilingual blog Buscaraons (entries in English, French, and Catalan—separately, not as translations of each other) has a series of entries (in English) on onomatopoeia in Catalan (scroll down to 24.11.03 Onomatopedic sounds in Catalan, then up to 25.11.03 To bark and to quack in Catalan and 27.11.03 More Catalan onomatopedia: to meow and to mow).
To purr is very interesting. The verb, when it refers to a cat or engine, is roncar. This verb also means to snore. So Catalans hear purring and snoring as identical sounds.