low voice when someone call me

Dear,

I have a BB z10 mobile phone and when someone call me I have a low voice from his side how can I repair this because it is possible there is a dust in the earphone of the phone

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0