noun
being able to hear everything; overhearing clearly
Used when a conversation or sound is completely audible, often unintentionally or when it was meant to be private. Common in phrases like 丸聞こえだ or 丸聞こえになる.
隣の部屋の話が丸聞こえだった。
I could hear everything from the next room.
声が大きすぎて、会議の内容が廊下まで丸聞こえだよ。
Your voice is so loud that the meeting details are completely audible out in the hallway.
筒抜け also means that something is completely audible or that information leaks, but it often implies a direct path (like through a pipe) and can be used for secrets spreading. 丸聞こえ focuses on the state of being fully heard, often unintentionally.
Compound of 丸 (まる, 'whole, complete') and 聞こえ (きこえ, 'audibility, being heard'), from the verb 聞こえる (きこえる, 'to be audible'). The reading ぎこえ is a rendaku (sequential voicing) form.