The Google AdWords blog announced yesterday that they have begun inviting advertisers to test out Google Audio Ads. The test is only running in the US. If you want to be part of this test, you can apply over here. After you get accepted, make sure to read Guidelines for Audio Ads, describing how you can use MP3 or WAV files, both 30 seconds long, with no long periods of silence and only containing one ad (no sharing). More details on how this is working at the Google Help section of the audio site.
I am just curious, when they are going to change the logo from Google AdWords to Google Ads. Then have sub products under Google Ads, for AdWords, AdSense, Audio Ads, Print Ads, TV ads and Virtual Reality ads.