I assume you are referring to audiobooks?

Definitely reading as it enables you to go at your own pace, skip back a few words if you didn't catch a meaning, or stop and stare out of the window for a few seconds.

Also the reader of an audiobook imposes their own interpretation of the text whereas if you read there is nothing between you and the author.

You can sort of do these things with an audiobook but it's fiddly.