What is the difference between two sentences?
He had to raise his voice to be heard by the audience. AND
He had to raise his voice in order to be heard by the audience.

Question

What is the difference between two sentences?
He had to raise his voice to be heard by the audience.  AND
He had to raise his voice in order to be heard by the audience.

Answer

Yes, there is no difference. We tend to add in more detail in sentences in English sometimes just to make our meaning more clear or to emphasize a point. We can leave out the "in order to" and the sentence still has the same meaning. In order to just means, 'as a way of/to', so in this sentence it is just clarifying why he raised his voice.

Answer

There is no difference in meaning.