If you have set your phone to Silent Mode, then you will have an icon of a musical note with a line through it on the display. To turn off Silent Mode, press the # key.
When you are on a call, does Speakerphone work? To activate this, during a call select More and then Speaker. If this produces no sound, then it is more likely a hardware problem than a software problem.
Try powering the phone off and then on again. Sometimes this can fix things that don't seem to be working.
Finally, it is worth trying a Software Update if the phone is still not playing sounds through the loudspeaker. Even if the software is up-to-date, and it allows you to update, do it anyway.
If none of this helps, click Contact us at the bottom of this page to find the contact info of your local Sony Ericsson support dept.
