I am not certain what you call a 'large class'?
As a university lecturer I have had groups of over 100+ and the issue you raised can be a problem. You know as a trained teacher, that most students have a concentration span of only 40 minutes and this is then the most important period for you as a teacher, especially with a large group.
Every one of your students will bring with them into your class a number of issues, whether it be personal, emotional, or educational, and as a teacher you have to be able to deal with these.
The easist way, for me anyway, is to intoduce short periods of visual and/or audible displays and to develop short ( about 10 minutes ) practical exercises for your students to undertake. These should be devised to allow for groups of any size, including the student who wants to work on his own.
By introducing peer support and communication within your large group you should find that the group begins to gel and will work and think together.
As a teacher with a large group your role is somewhat as a facilitator, and as long as you keep the 'topic' on track, you will achieve your lesson goals.
Hope this helps