My iPhone 5 speaker does not work properly?

I have a similar issue and think its software related. Siri sounds very tinny in the iPhone 5 compared to 4s. Lock sounds, key sounds also much quieter but get better if you turn them off and on - hence why I think it's software prob. Same with external speaker and headphones.

Please Apple release update. Call volume is great in mine, just Siri sounds terrible and low lock and key sounds.

I just spoke with apple support. She had me do a hard reboot and reset all the settings. Neither worked. Next step is to restore the phone to original settings. If that doesn't work I need to mail my phone in and wait several weeks for a new one or pay $29 and only wait three days. Not cool.

I'm really hoping it's a software update that will be fixed with an update.