When you make a phone call on your iPhone, you have the choice of hearing sound through either your ear piece or through the iPhone's built-in speaker. It's also possible to listen to music from the iPhone's iPod through a speaker, rather than via headphones. No matter which of these functions has necessitated that you use your iPhone's speaker, adjusting its volume to make it louder is a simple, straightforward process.
Make a phone call and switch on your speaker phone by tapping the "Phone" icon, entering a phone number or selecting one from your phone book, tapping "Call" and then the "Speaker" button.
Tap the "iPod" icon, then the name of an album or artist and then the name of a song to play the song.
Turn your iPhone speaker's volume up. Press the top half of the button on the top-left side of your iPhone screen, tapping successively until you have reached your desired volume. It's important that you either be making a call or listening to a song when you do this since pressing this button on an idle iPhone simply turns up its ringer volume.
Check your iPod application's volume limit if you turn your speaker all the way up and it still seems soft. Tap "Settings," "iPod," "Volume Limit." Slide the circle on the blue bar all the way to the right to increase your iPod's volume to maximum.