Background noise could distract the people you are communicating with, for example if there is music or somebody else talking. This would make it hard for the audience to concentrate and make the person doing it feel uncomfortable. To overcome this you would tell the audience politely to stop talking and listen to you, or if they had to speak or wanted to listen to music to go into another room. Also a noise in the background would prevent the audience from hearing correctly.

 

 The audience may loose interest due to distractions from other people in the audience doing things which distract others, for example if people were talking and not listening or on their phones. To overcome this ask them if they need to speak or use their phones go into another room, if not to try e quieter. It would also be hard to concentrate on a speaker when you are not physically comfortable. To make yourself more comfortable you could make sure that you are not to hot or cold, or that you have a drink of water with you so you are not thirsty.

Lack of concentration is a barrier of communication, including not listening clearly for example if people were talking. Most people have to concentrate on one thing at a time leaving them not listening to the person doing the presentation. To overcome this they could leave the room if not interested instead of distracting everyone else or having full concentration on the person talking. Also lack of concentration from the people in the audience could cause a lack of concentration to the person delivering the presentation due to people talking or using their phone.