phone randomly makes siri beep

I think I figured this out!

It is the Raise to Listen setting. I found this after realizing a bunch of my friends were getting random audio messages after hearing this beep. I can now reproduce it quite often:

1. Put the cursor in the "iMessage" box in Messages and make sure it is blinking.
2. Raise the phone to your ear quickly (or make a similar type motion).
3. The phone will start recording anything it hears. If no sound is detected, I get the Siri "beep".

To resolve, go to Settings > Messages > Raise to Listen and slide it off. Don't believe the BS explanation below the button. It is not only for listening to or replying to incoming AUDIO messages, it must be setup to reply to ANY messages.

I've been trying to pay more attention to when this happens, and it seems to happen in the following situation.

1. I have just finished sending a text message (the message may still even be "in transit").
2. I am turning the phone over to either place it in my pocket or set it face down.
3. I am hitting the sleep/wake button to lock the phone and dim the screen.

I'm not positive on #3, but for the past week or so, every time it has happened I have been using the sleep/wake button. Do you guys typically use this to lock your phone while you are putting it in your pocket?

im also having that problem. I didn't think it would be a big deal when I first heard it happen but it seems to occur more and more over time. It's rather annoying. I try to send a quick text and the noise makes it very obvious. It seems to happen whenever I'm putting my phone screen down. Most of the time it is when I'm sending a Text. I hope this thing can be fixed easily, and we don't have defected phones!

This happens to me on exactly the same conditions, when i'm texting, i turn my phone over face down and the screen goes black and makes the siri noise, when i pick it back up and turn it over the screen comes back up! how odd?

Same problem here on my iPhone 6+ iOS 8.3. It makes me want to throw the phone through the wall because it happens at the most inopportune time... like in a meeting! It's so loud also. It always happens after I sent a text or iMessage and I set it down on the desk. I'm 99.9% sure I'm not hitting the home button or anything. I mean it would have to be held down anyway. That's exactly what the sound is.

That's the thing. I actually NEVER turn the ringer or have the switch on. I always rely on vibrate. Frankly I think cell phone ringers are obnoxious in public. As I say this a client in my meeting just had his phone ring and interrupted it. :-D

But the mute thing is even more of a reason why this is truly bizarre.

Yes was just thinking about the appointment. I've done this backup/restore on like more than half a dozen phones. I should go back to restoring with the Mac backup. It's been awhile. Usually the thing that takes the longest is the app restore. Anyway, I apologize for straying off topic. I hope others find a solution to the issue without having to get a new phone.

I still have this issue as well on 9.1.

My issue mainly happens right after a imessage is being sent or just finished sending and I put the phone down. There is a Siri beep that sounds.

I have the Siri beep sound turn off unless I'm using bluetooth or a handsfree device, so the home button cannot be failing, as when I normally press the home button the phone only vibrates.

The home button on your phone may be failing.

I have the same issue with my iPhone 5S on iOS 8. The sound plays even though my physical mute switch is turned on.

You don't mute your phone when you go into a meeting?

Take it in for service, there may be a problem with your home button.

And even more of a reason to have it looked at.

I think you're right. Might have to run up to the Apple store this weekend. It's a bit of a drive but it's always worth going up there. ;-) More fun restoring a new phone if it gets replaced. Thanks!

Make sure you make a Genius Bar appointment before you go and do both a computer backup and an iCloud backup. I find it faster and easier to restore from backup on the computer.

simply restarting seemed to work for me.