You may not always be the speech presenter or speaker. Many times, you'll be in the audience yourself. Active listening is a skill that can make you a more effective speaker in the long run.
1a. Courtesy
Being an active listener not only makes you a more engaged audience member but, quite simply, it's polite. If you expect people to pay attention to your words when it's your turn to speak, they expect the same from you.
There are a number of other courteous behaviors that an active listener should practice:
1b. Attention
Active listening refers to the practice of not just hearing someone, but really listening and paying attention to what they have to say. Intrinsic to active listening is the ability to feed back what has been said to the speaker, often in the form of paraphrasing.
As an audience member, you might not have the opportunity to actually verbalize these feedback in the moment; however, a true active listener is able to summarize at the completion of the speech.
1c. Open-Mindedness
You may not necessarily agree with everything that is being said. It's important to come to the presentation with an open mind— that is, to at least listen with respect and courtesy to ideas that may be in conflict with your own personal beliefs and values.
Again, if you expect others to be open and receptive to your ideas, you must extend that same courtesy to others.
Source: Source: Boundless. "Rules to Follow When Listening." Boundless Communications Boundless, 27 Feb. 2017. Retrieved 27 Jun. 2017 from https://www.boundless.com/communications/textbooks/boundless-communications-textbook/public-speaking-ethics-2/significance-of-ethics-in-public-speaking-23/rules-to-follow-when-listening-111-7088/