That would probably wreak havoc on your battery life.
Here's what I do instead:
I set it up so that my google voice messages and transcriptions get sent to my gmail account. From there you can set up a filter which forwards all emails from google voice to your vtext gateway,
yournumber@vzwpix.com. That way, when someone leaves you a voicemail, it gets forwarded almost immediately to you as an MMS message - so you get the notification as well as a transcription in a SINGLE text message. (as opposed to having google voice forward the transcriptions directly to your phone as several consecutive SMS messages)
By doing that, I've actually been able to set the notification interval on google voice to the max setting or even turn it off completely.