No one there could believe their ears for even a second.
Everyone was so shocked, they had trouble believing what they heard.
この場合、次のような言い方ができますよ。
ーNo one there could believe their ears for even a second.
「そこにいるみんな誰もが一瞬耳を疑った」
could not believe one's earsで「耳を疑った」と言えます。
ーEveryone was so shocked, they had trouble believing what they heard.
「みんな驚いて耳を疑った」
had trouble believing what one heard で「耳を疑う」とも言えます。
ご参考まで！
カナダ 
