I was testing the device , in the Setting > Accesibility > SST 

i turned it on , after that whenever i touch the screen some voice response are generated by the system,

to get rid of that i turned of the phone and when i switched it on again , nothing is happening , wherever i touch on the screen there is no response ,

the only sound coming are

1. when screen is unlocked by the side key – “Screen is Unlocked”

2. When screen is locked back by the side key – “Screen is Locked”

3.When charger is connected – “Charger connected”

4.When charger is removed – “Charger disconnected”

apart from this nothing is working , the phone is good as dead ,

everything was working fine before i switched the above mentioned feature on.

is there any way i can reset the handset to previous settings.