There are some conditions where receiver puts up hurdles to communication (like as defensive shield against unwelcome questions). Today's 'professional' politicians, are frequently skilled at avoiding question. Extensive media training, frequently given by former journalists, aids them to replace the meaningful answer to interviewer's question with their own, frequently anodyne, 'sound bite'. These 'non-answers' can sound very convincing, and you have to be very alert to spot them.
From the interview on radio and/or television. Create note of tactics utilized by interviewees and methods that interviewers try to get answers. How successful are they? Recognize those occasions where the 'non-answer' is accepted, and others where interviewer does get the meaningful reply.