He needed a sounding board rather than thinking alone.

他需要一个参谋，而不是独自思考。

《柯林斯英汉双解大词典》

Your body is a sounding board.

你们的身体是试探水深的船板。

youdao

I spoke to him nearly every day, using him as a sounding board.

几乎每天我都要与他高谈阔论一番，他就像是一个听众。

youdao

"This is a rough-and-tumble place and it's nice to come back to two people who care about me, who care about my success, who care about the difficulties I might be having either at work or at home and just to have two friends who are a sounding board."

VOA: standard.2010.08.07

They both felt it was going to be great to have a sounding board.

WSJ: The new book group? Women form 'Lean In' circles

Finally, he asked Moore to fly to Washington to serve as a sounding board, along with a team of other AGs and trial lawyers.

CNN: McCain's Big Deal

She served as a sounding board for his scientific ideas and helped to check the math in his papers, but eventually their relationship disintegrated.

NPR: Einstein: Relatively Speaking, a Complicated Life