Thanks, tried that but it still doesn't give an activation tone. Siri works fine and responds to my questions. It just doesn't produce the familiar beep when activated either initially or when the mic is tapped. I tried restarting my phone but it had no effect.
I noticed this too and it's like this on my husbands and daughters phones as well. I kind of miss it since I use that sound while I'm driving as an indicator as to when to start talking so j don't have to look at the screen. I did just ask Siri where her sound went and this is the response I got..
I have gone back to my 5s and updated to iOS 9.0. Strangely I can get the voice feedback from Siri in the 5s but not the 6 plus. I have put both phones side by side to ensure I have not missed anything in the settings but the settings are all the same. Strange. Anyone missing Siri's voice on a 5s?
So I reset my phone last night. Went through all the trouble, had to put all the stuff you mentioned back, etc. The audio prompt returned...until this morning. It's gone again. What a pain.
Yet the iPad still has the prompt. Can't figure that out.
I also noticed different features in my Gmail from my phone to my iPad. But that's a different thread I guess. (Phone Gmail is better)
So as it turns out, Siri going mute on the iPhone is by design. I've read it on a few different places on the web. In fact if you ask Siri "Siri, where are your beeps?" , she will reply things like "it much quiter this way".
But why does the iPad still beep, I wonder? http://ios9news.net/missing-siri-beep-sound/
I updated the iOS 9 on both the 5s and 6plus. Strangely I get Siri's voice on the 5s and not the 6plus. I've put both phones and checked the settings side by side over and over again, done "reset all settings" on the 6plus only but can't get Siri to talk. Let us know from each other the phones that the voice is missing. I suspect it is the 6 and 6 plus that have this problem.
I don't think it is a "problem". Our friend GOOGLE tells us it is by design on the 6 and 6+
And I also read that iPads still beep due to the fact that they don't have built in vibration motors, which makes sense. There is a lot of stuff on line now regarding this.
The other problem I have apart from losing Siri's voice, is that when I update my Apps OTA on the phone and synchronize with laptop in iTunes, the Apps don't upload into the iTunes and requires a second upload from the store in iTunes. Even backing up does not resolve it. With iOS 8 iTunes used to ask to tell you you apps that are on the phone that are on the phone that are not in the library and whether you want them to be downloaded. Now you are not asked; and the apps are not downloaded.