These sentences were read aloud by real people — native Japanese speakers — for the open Mozilla Common Voice project. Listen to how a phrase sounds in real speech: the intonation, the pace, the way words run together. Two speakers mean two different people read it — compare them.
ちゃんとリサイクルされてるのか疑問
ちゃんとりさいくるされてるのかぎもんI wonder if it's actually being recycled.
こんな疑問を抱いたことはありませんか？
こんなぎもんをだいたことはありませんか？Have you ever wondered about this?
そもそもこのサイトの録音を課題に指示した大学教授は何を考えているかも疑問に思う。
そもそもこのさいとのろくおんをかだいにしじしただいがくきょうじゅはなにをかんがえているかもぎもんにおもう。I also wonder what the university professor who assigned this site's recordings as a task was thinking.