There's a call recording app for the N9 (http://n9-apps.com/call-recorder). Unfortunately, its developer says it isn't beepless.

I still haven't bought my N9. Call recording is critical for me. The beeps in my E52 are unbearable. There are beepless recording apps for Symbian and there's also the possibility to patch the OS to prevent the beeps on any recording app.

Does anyone know where exactly is the beep coming from on the N9's OS? Can it be patched?

Actually the app IS beepless.

Just a translation misunderstanding when chatting with the dev.