How do dogs tell you their name?
This may be lengthy because I am going to give you an example. I can't tell you HOW, I have no word for the actual mechanism. But this is only one of many incidents I could give you.
While driving down a divided highway one afternoon, I saw two dogs running on the side of the road: a male Golden retriever and a brown Red Heeler. Not wanting to see them dead on the highway, I pulled over and called to them. The Golden came right over and willingly jumped into my car. The heeler held back a little, but seeing his buddy get in, he reluctantly followed. They rode in the back seat to my house and I talked to them, glancing at them occasionally in my rear-view mirror. It was obvious this was a big adventure for the Golden, but the heeler wanted no part of it and just thought it was a bad idea. I asked them their names, just making conversation. I said to the Golden, "You look like a Bubba to me. Should I call you Bubba?" Now, never in a million years would I call a dog Bubba. It just isn't my style. But I had to call him something and that's what popped into my head. "Okay, and what about your friend back there?" But the heeler wouldn't look at me. He wasn't giving me the time of day. I tried a bunch of names but nothing stuck.
When I got home I put them in the back yard with food and water and called the local shelter, giving a description of the dogs and my phone number. Nobody had listed them missing. I ended up keeping them for two or three days, then I got a phone call.
"I understand you found a couple of dogs ..." Yup. It was the owners, who'd been out of town a few days. They'd left the dogs with a friend, but they'd broken out and headed for home, when I found them.
And just out of curiosity, what are their names? "Well, the Golden's name is Bubba ..." (!) ...."but we've never been able to settle on a name for the Heeler. Evetyone in the family calls him something different." (! again!)
Again, I can't explain it.

It just happens.