I do know the C7838WIP/C7835WIP/C7837WIP from Vstarcam have audio recording to the local MicroSD. But understand that recording (ONVIF) to their ZAFEGO NVR does not have audio as they are still trying to resolve the audio capturing portion for Vstarcam.
QNAP last tested can capture the ONVIF from VStarcam's C series, but I don't remember hearing any audio at all.
Not sure if DLINK's NAS can capture audio recording for their range of camera, but seriously, most of the consumer level cameras are not able to capture audio that can be treated as evidence so far that I have played around with...