The truth is only heard

 by the ear that will listen.

When the cost of life is too great,

 death affords the difference. 

The factory of lies emits a lot of smoke,

 Be careful of those who fume. 

He who will not hear a matter 

often rejects the truth. 

When you ask those with opinions to leave, 

you sometimes ask those with the truth to get lost. 

Sound advice 

needs not make much of a sound. 

When your crime is that you've spoken against the state, the state is the one committing the crime.