Can't assign guest audio to dedicated sound device on Host

[random_luser]

I would like to assign all audio from a Guest into a specific audio device so that my kids can listen to audio on the Guest while I work on the host or other guests. I am using Windows 7 64-bit as Host.

The simplest solution would be to allow the guest audio to be directed to a specific audio device. This is possible using windows APIs, but in absence of choosing a device, VirtualBox sends all audio to "Default Device", which is then the same as all other Guests, as well as the Host. Therefore, all audio is mixed into 1 stream, which prevents isolation.