Hi,

Have you checked the ringtone settings in Menu > Tones > select a ringtone > OK?

Do you get a ringtone sound when you do this?

If not try:

Increasing the volume of the ringtone by using the arrow up key on the phone.

If still not:

Try using the phone in loudspeaker or hands free mode (phone away from head) on a call to prove that the loudspeaker is working. This is the same speaker that is used for the ringtones.