Video and Text
Listening is listening. Reading is reading. Reading along with an audio track can improve understanding of a text, but listening without the written word is no different from having the radio or TV on in the background. (And by the way, it stops being background noise when a listener starts spouting the same spin [insert news network here] uses.)
Listening to one person read, while entertaining and convenient (jog, drive, nod politely while a seatmate on the bus drones on), is also limiting. The video I'm adding to this post shows how one phrase can be read in different ways. There are other examples around that show how a single word can mean something entirely different depending on how it comes out of the human mouth. Pauses in reading can happen at different points, whether to take a breath or to audibly separate one idea from another, even when there isn't any visible punctuation in the written form. One person may change a sound or take a pause in a particular spot, but where would you pause or alter your voice if you were reading on your own? You can only answer that question while, you guessed it, reading on your own.
This point is a bit of a tangent, but there's another limitation involved with this issue. While there is an enormous appeal to being able to carry a library in less space than is taken up by a magazine, there's still a tether there: either to a particular device or service, or literally because of a physical power cord. (Another aside - there's an anti-literal bar that almost makes me wish I drank more alcohol, only because I want to drink there.)
Audiobooks can and do enrich, but don't let them supplant your own understanding.