How to raise Siri's voice volume on iPhone 14 Pro?

Invoke Siri. While the colored spinny thing is on the screen, use the volume buttons to adjust the volume.

I think there's a bug in iOS 17.6 and the Siri volume gets stuck, for me it got stuck at max volume and it was very annoying. Because Siri has no UI for its own volume on the front end, the only way to get it working again (similar to turning a setting off and back on) is to tell Siri to speak softer or louder. After you do this once the volume button should start working again. It's possible I needed to be playing music simultaneously but whatever that got Siri to stop alerting the neighborhood when I turned off the lights.

One way is to tell Siri “Turn up the volume.”