Not directly, no. The circuit you have now is an integrated product with DSL plus POTS. You may be able to order a new standalone voice service, at a cost that totals around $23/mo with taxes and fees. There is also an activation charge which I believe is $150.
If you did proceed along that path, after it was activated and after you have the wiring connected (which we can do for an hourly technician fee), you could then port your number off the DSL circuit and initiate a disconnection of that service. Sorry, not a really easy process, customers seldom are interested in this and it’s not something we have well optimized for.
The other routes are to switch to a new Sonic product like IPBB (which uses the ATT Uverse platform), which includes moving your number to the bundled VOIP service, or if we haven’t got a fast enough offering there, consider a Cable product and port your number. Or consider an over the top VOIP product as a last resort.