iPhone speaker's volume is very low

What mac, what sound output, what application…

Writing an effective Apple Support Communities question: https://discussions.apple.com/docs/DOC-5931

I see now that this is about iPhone, your post was originally in the Ventura forum, that is why I assumed it was about a Mac.

Did this change recently? Any other change like a recent update that may correlate to this issue?

Just to set aside the obvious: you are pressing the volume up button and seeing that the volume is at max?

As my own hearing is not so good, especially in noisy environments, I often need to set the phone on loudspeaker mode in order to properly hear the other person.

I have been using a miccus Bluetooth extender on my Vizio tv with my Sony headphones now trying to connect my new beats studio three for the first time to same

Sorry I got Bluetooth connected it just a very low volume

My iPhone 8 decreased volume all system apps why?