yea, i agree with PPC-Coach, Infact I just close the page wer a audio loads, i dont even try giving a second look at that page.. nt a good idea trust me!!
All the posts above mine have said it. I wouldn't enter a page if audio ads were in it. Unless there was something there I really wanted. And they wouldn't click on the ad, instead just hear it really.
When you say google audio ad..are you talking about the Radio Ads thats now avialable on adsense? You need to be more clear on what this has to do with google. I don't think google is offering any one page audio ads at all. I could be wrong. As the consensus goes an audio ad just auto playing on a page is one of the most annoying things. Specially if you have to scroll the page to turn it off or find where its comng from. This is like 10 times worse when you using multitab browser with a couple windows open.
Audio sucks! And its always some really cheesy voice that is probably not what you're intended audience wants to hear e.g. a UK visitor would not want to hear a US voice and vice versa.