The raise to speak feature on Siri does not work

I am a new user of the 4S coming from HTC droid. I love this 4s baby. Have been doing a lot of reading in a lot of posts to learn more about the phone and its features. All have been very helpful.

I too had a lot fail attemps to use "riase and speak and the post by Frank seem to have taken care of the problem. I am now getting 100% success.

I am not sure the following had any impact but on the phone key pad I moved from "recents" to "call"

Thanks to everyone for all the help throughout these posts!