Paragraphs and sentences can be too short or too long, making reading difficult. Rewrite the following text to read with more flow:

The presentation began slowly. It gathered pace halfway through when the subject matter became more exciting as a result of more controversial ideas being introduced along with a more animated tone of voice from the presenter and the fact that the volume of the sound system was turned up to a higher level.
The controversial nature of the subject caused the audience to react by becoming restless and muttering.
The speaker seemed oblivious to the response of the audience and carried on regardless.
As an example of a presentation the event was a disaster, with some of the audience walking out toward the end.
The organizer asked those who left early to say why they were leaving. Some said they were offended. They said the presenter was too opinionated. They complained the sound was poor. Others said they wanted more information and evidence of the views presented, not just an unsubstantiated and biased and ignorant expression of belief.