I found this bowl that records your voice, and every time your dog eats/drinks out of the bowl, it plays a recording of your voice - for when you're away for a while. They're half price right now ($18) and includes shipping.
It's only for the next 6 days so here is the link in case you're interested:
https://doggyloot.com/deals/174-18-d...ludes-shipping
Anyway, I have no idea if it works, but I'm gonna give it a try.