If you'd like to browse the library's collection of books on CDs (or other formats such as DVDs or large print books), you can do so through the catalog's Advanced Search feature. First, click on the Explore tab, then look for the search field in the top right corner of the page. Click on the Advanced Search link under the red Search box.
The Advanced Search gives you several limiters for narrowing down your search, including availability at a particular library location, age group, and others. To browse a certain format, go to bottom of the page to select the formats you wish to peruse. Audiobooks on CD is the first one listed. If you're only interested in a particular title, subject or author, you can type that information in the search field (the one under 'include' near the top of the page) before applying your limiters.