"A good man brings good things out of the good stored up in his heart, and an evil man brings evil things out of the evil stored up in his heart.  For the mouth speaks what the heart is full of"-Luke 6:45 (NIV).  

Solomon said the prudent hold their tongues (Proverbs 10:19); therefore, we need to use it less and listen more!  There is wisdom to be gained by listening.  James 3 says you can determine an earthly heart from a heavenly heart by the words a man speaks.  Earthy speaks evil: envy, selfish-ambition, disorder, unspiritual, demonic...every evil practice (v.14).  But, Heavenly speaks good: purity, peace-loving, considerate, submissive, full of mercy, good fruit, impartiality, sincerity...every good practice (v.17).  By listening you can determine if a person's heart is good or evil..but, you have to listen.  Shhhh!