voice is very loud when I unlock my iphone XS

I am using an iPhone Xs with iOS 12 and I have found the exact same problem. Sometimes, when unlocking the screen, the voice sounds very loud suddenly, and then returns to a normal level.

Cannot solve this at this moment.

This is happening on my iPhone X, and has started happening since the IOS12 upgrade. You can help by reporting the issue to accessibility@apple.com

Was running the iOS 12 beta on a six End it did not have this problem, have had this problem since I got my iPhone XS

Hi guys!
I got my new fancy iPhone XS a few days ago, and i also experience this bug every time I unlock the phone. Did not see this running iOS 12 on my iPhone 8, both betas and official release. So this seems to be a bug only affecting the phones without a physical home button, or phones with Face ID, if you'd like.
Very frustrating, especially at night when I want to listen to something on my phone, and don't want to wake up my wife and our 7 months old baby sleeping on the same bedroom!
But what I've figured out is that this is related to Siri volume. So if you turn Siri volume below the VoiceOver volume, the oposite will actually happen. When first unlocking the phone, VO will speak quieter than it should and bounce up to the set VO volume after perhaps 0,5 seconds.
Try activating Siri, and just be on the Siri screen while hitting volume down until the Siri volume is really low, and then try again to lock the phone and unlock. You will now hear that the screaming start of VoiceOver speach is gone.
I need to report this to Apple Accessibility, but haven't had the time to do so yet, so I'm very happy if someone else also are willing to take the time to tell them about this bug.
Hope this helps :)

Thank you very much
This is very helpful I will be sending an email off to Apple accessibility