An Alert-Info header would have to be inserted in the SIP INVITE sent by the SIP provider. This cannot be done by the user.
Google Voice is not a SIP provider and does not use SIP INVITE's, consequently this is not possible with Google Voice.
The OBi provides 10 pre-defined distinctive ring patters to select from, and any or all of the can be redefined by the user as desired. See page 95 of the OBi Device Administration Guide.