By talking loudly she tried to show her irritation.

[Urus]

Hello!

Would you please explain to me. There are some sentences I have come across. The second version of every sentence is my conversion.
Can I convert these sentences like this? Is the conjunction "by" needed in every of these sentences (and why)? Have I placed the commas correctly?

She tried to show her irritation by talking loudly./By talking loudly she tried to show her irritation.
People often hurt each other by saying unpleasant words./By saying unpleasant words, people often hurt each other.
He was embarrassed by winning the first prize./By winning the first prize, he was embarrassed.
By taking the pill, you can reduce pain./You can reduce pain by taking the pill.
He irritated the teacher, by often coming late. /By often coming later he irritated the teacher.

 

[5jj]

The sentences with the b'y' + -ing form second are more natural. Neither version of the third sentence is very natural.

The 'by' is necessary. It conveys the idea of how the main situation comes about,