Chromecast Audio is a powerful tool that can be plugged into the home speakers to play music or audiobooks for you. It must be an enjoyable experience when you play Audible audiobooks with Chromecast Audio. However, unfortunately, Audible does not support this tool. But we still find some methods to stream Audible audiobooks on Chromecast Audio.

Cast Audible Audiobooks Directly
Chromecast Audio is very friendly to cast music from an Android phone. Please make sure you have the tools including Google Home app, Audible Manager app, Chromecast Audio, and Android Phone. Then you can follow these steps:

1. Plug the Chromecast Audio into your speaker and insert the power adapter into an electric socket.
2. You should make sure that the speaker, Chromecast Audio, and the Android phone are connected to the same Wi-Fi.

3. Download the Google Home app on your Android phone and launch it. It will detect the Chromecast Audio which is connected to the same network.

4. Go to the side menu of the app > Tap the Cast Screen/Audio button > Select the casting speaker you want the audio to play.

5. Run Audible on your Android to play the audible books, it will stream to the speaker automatically.

This method works perfectly for users who have an Android phone, but it doesn't work for iOS or Windows phones or any other third-party casting apps for the reason that Audible AA and AAX files are protected and not recognized well outside Amazon's ecosystem.

Stream Audible Audiobooks on Chromecast Audio Freely
Fortunately, many third-companies with a long-term view have found the requirement of users to enjoy Audible audiobooks freely and develop a series of software such as Aimersoft Media Converter, TuneFab Apple Music Converter, TunesKit Audible Audiobook AA/AAX Converter. They can all convert Audible audiobooks into popular formats of music files. But this has the easiest accessibility is TunesKit Audible AA/AAX Converter. You can bulk drag and drop to import Audible files and use one click to output MP3 files with up to 100X speed. What I can say is that the speed will surely outperform the similar products in the market. The complete free trial version is readily available if you want to try it out.

Detailed steps to convert Audible audiobooks
1. Import Audible audiobooks

In order to convert your files to MP3 format, you need to download the Audible AA or AAX files on your computer first. If you haven't downloaded them, you can log in to your Audible account and then follow the official tutorial of Audible to download through Audible Manager on Windows or iTunes on Mac. When it is done, you can drag and drop them to the TunesKit Audible AA/AAX Converter.
2. Set output format

TunesKit Audible AA/AAX Converter set the default output format of audios like MP3, you may keep the default settings for streaming. But if you want to make your output files more personalized, you can also adjust select the codec, channel, sample rate, bit rate and adjust the volume, speed, and so on.
3. Convert Audible AA and AAX files

After confirming the settings, you can click the Convert button, TunesKit Audible Audiobook Converter will start to convert all the imported Audible books in the batch.

4. Stream audio files
Finally, you can upload these Audible audiobooks to any devices such as phones, tablets, computers or cast them on your Chromecast Audio via Chrome browser or supported castings apps such as Google Home, Google Play Music, and many more other devices.
Summary
These are the 2 methods to stream Audible audiobooks on Chromecast Audio. If you choose the second method, you only need 3 simple steps, you can break the limitations of Audible audiobooks and play Audible on LG TV, Samsung TV, and any device you want.

For more: https://www.tuneskit.com/audiobook-tips/cast-audible-audiobooks-on-...
Download TunesKit: https://www.tuneskit.com/audible-aa-aax-converter-mac.html