Hi @Mullah, let me see if I can help out here!
Have you been able to carry out a quick test of the speakers in the device using the support app? In order to do this, find and tap Settings > Support > Xperia Tests > Speakers and microphone.
Also, it would be great if you could try to reboot your phone in safe mode to see if the loudspeaker works better there. All apps downloaded from Play Store is temporarily deactivated while in safe mode and by doing this, you can see if this behaviour is caused by a downloaded app. For more information on safe mode and how to use it, click here.
Try these measures and let me know how it goes!
