発言, 発音, and 発声: content, pronunciation, and voice
Compare a meeting remark, word pronunciation practice, and vocal exercises before choir practice. Identify the content or sound each activity concerns.
The content of an utterance
発言 (はつげん) refers to an utterance or remark. 「会議では相手の発言を最後まで聞こう。」 proposes listening to the other person’s contribution until the end.
In 「彼女の発言をきっかけに議論の方向が変わった。」, her remark prompted a change in the discussion’s direction. The focus is a contribution that affected the discussion.
How a word is pronounced
発音 (はつおん) concerns pronunciation. 「先生の後に続いて単語を発音した。」 describes pronouncing a word after the teacher.
「難しい発音を何度も声に出して練習する。」 describes practicing a difficult pronunciation aloud several times. The object of practice is the sound of words, rather than a position advanced at a meeting.
Producing and developing the voice
発声 (はっせい) concerns producing the voice. 「合唱の練習前に全員で発声を行った。」 says everyone did vocal exercises before choir practice.
「舞台に立つため、腹から声を出す発声法を学んだ。」 says a method of producing voice from the abdomen was learned for performing onstage. That purpose does not report a completed stage performance.
What did everyone do in 「合唱の練習前に全員で発声を行った。」?
Show the answer and why
They did vocal exercises before choir practice. The sentence concerns voice production; it does not say they made meeting remarks or practiced the pronunciation of a particular word.