Effective Telephone Techniques Training As an example only, we have previously covered: How you sound on the telephone. How to establish trust and credibility with the caller. Why people don’t understand what you are saying. How to instil confidence into the caller. How to use positive language and not negative language. How to use ‘body language’ when talking on the telephone. How to prevent sounding boring, over powering or disinterested. How to create the right impression on the telephone.