Nope. Call tracking is difficult and expensive, both in terms of money and complexity; I'd have to 10x my prices before even touching it. You also wouldn't be using a Google Voice number -- call tracking services work by renting huge numbers of phone numbers, and assigning a unique number to each visitor to your site for some time. Each person sees a different number, and their calls get routed to whatever your real number is after being logged for analytics. Improvely only tracks stuff that happens on your website.