From what I have learned, on June 4, 1940 Churchill gave his great second speech to the house. There was no contemporaneous recording, it being against the rules of the House at that time. Likely the same or next day the speech was printed in the papers, and read on the radio by BBC announcers. On June 18th, it is apparently quite clear that Churchill himself did record the speech in a studio for the BBC, which recording is on the net at https://www.winstonchurchill.org/resources/speeches/1940-the-finest-hour/we-shall-never-surrender/ . In that recording, his voice is quite calm and very determined sounding, but not apparently unduly raised or agitated. In the trailer for the recent film, "Darkest Hour", however the actor does raise his voice considerably in the scene in the House chamber. Is there any actual evidence for this interpretation, or was this just the director's supposition? To me, it makes a difference.
It is a long speech, roughly 4,000 words, of which I doubt more than a paragraph or two is repeated in the movie (which I have not yet seen). Churchill was an accomplished orator, likely one of the best ever in the history of the English language. Part of that skill is matching the emotion of the message to the emotion of the delivery. In a speech calling for calm determination in the face of a bitter-sweet accomplishment, anything other than a calm delivery would be out of place - except in a Hollywood movie.
For these reasons I very much doubt that the delivery in the House of Commons was significantly different than that on the BBC.
Here is the entire Hansard record for the day, by way of context for the speech. One will note that no attempt is made by Hansard to record anything other than the actual words spoken, with their utterer. Any interpretation of emotive delivery, after the fact, could be only on the basis of personal recollection, with all the attendant uncertainty from the possible errors and conflicts inherent in that.
At Harrow School,his alma mater,Churchill was asked by a schoolboy something like, "How do you succeed in life?"
His answer was "Never, never,never...[numerous nevers] give up."
No histrionics, just an example of quite and persistent determination. (Churchill was known as a "bulldog.") So "calm and very determined sounding, but not apparently unduly raised or agitated," sounds about right. Churchill knew that one way to beat the Germans was to outlast them.