I understand the word "amplified" and "sound", but not sure whether you are referring to Music, videos, Ringtone from a caller etc.
For the moment, here are some ideas.
Use Control Centre > Move Sound "Slider" upwards to the top (Maximum) or use the Sound button on (usually) the left side - it's the upper one of the two, and hold it down till the slider (top of screen) shows maximum.
Open Settings > Sound or Sound & Haptics > Under RINGTONE AND ALERTS, drag to slider to the right (maximum).
Open Settings > Music > Scroll down to "EQ" and choose a "sound" you think the loudest - surprisingly "Late Night" is about the loudest.
That's a start. If you meant sound whilst wearing headphones or ear pods, there are different settings, but I presumed you mean on the iPhone generally.
Perhaps you could advise?
Ian