Yes, and yes. Audiobook rights are very lucrative these days. I was just talking to an author friend who received $400,000 for his next series. I have multiple six-figure contracts for audio and one that is seven digits.
But signing those contracts WILL cut you out of the big five. There have been recent changes where they will ONLY sign contracts when audio is available - no exceptions. I suspect you’ll be able to find small smaller presses that will still take on print/ebook. Or you can self-publish.
If you DO sign your audio to the publishers you should know that (a) your royalty rate will be considerably less (depending on how the right is exercised it can be anywhere from 3.5% to 7.5% whereas when you sell directly to an audio producer you can expect 7.5% to 15%) and they won’t increase the advance in the same amount to offset the loss of advance that the audio producers are offering. For instance, say you can get $10,000 for your audio rights, you MIGHT get a regular publisher to give you $15,000 but that is probably 100% attributed to their P&L based on ebook and print and they SHOULD have raised their advance to $25,000 if audio is attached, but they won’t. They MAY up it a few thousand, but that’s a low-ball offer given audiobooks are the fastest growing segment of the publishing landscape.