日語 Japanese Ask Questions Thread2 質問

If you have a question about the language, ask it and fellow 4channers might see it and answer it for you.

Japanese - Ask questions thread
http://dis.4chan.org/read/lang/1174719097/l50

Is there any respectable dictionary online to look up Japanese sound words? Not talking about those terrible sites which only have like 100 listed. Like 擬声語/擬態語/擬音語 (honestly I forget which is which)

cause when I see stuff like ゴオオオオ
or オーム in the background I have no way of understanding it.