soundless
adj. 无声的；寂静的
例句
Her lips parted in a soundless scream.
她张开嘴想喊，但喊不出声来。
《牛津词典》
My bare feet were soundless over the carpet.
我光脚踩在地毯上没有声音。
《柯林斯英汉双解大词典》
A voice, soundless yet perfectly real, said, You are safe now.
一个无声而又十分真切的声音说到：现在你安全了。
