Describe three different barriers , management homework help

Please respond to the following in 1-2 sentences each:

Describe three different barriers to effective listening and how they develop in the workplace.
Describe some basic steps you could take to remove existing barriers in your current workplace (or classroom).
Describe the different types of listeners and how a business leader might develop employees to become active listeners.
Discuss how instant messaging and videoconferencing influences communications components
Explain when would it be appropriate to use instant messaging in the workplace. Provide an example. Determine the benefits and the challenges.
Justify when videoconferencing be appropriate in the workplace. Provide an example. Explain the benefits and the challenges of this approach.
When thinking about the history of public relations, determine which development do you think was the most significant. Explain your reasoning.
Of all the articles you found on the Web site for the World Advertising Research Centre (WARC) at http://www.warc.com/, determine which was the most applicable. Explain your rationale.
Explain how can this information help you communicate effectively with these professionals.