loud (of a voice)
彼は声高に自分の意見を述べた。
He stated his opinion in a loud voice.
声高な議論が会議室の外まで聞こえてきた。
The loud argument could be heard from outside the meeting room.
デモ隊が声高にスローガンを叫んでいた。
The protesters were shouting slogans loudly.