Translation of "Announcement" into Japanese

After the announcement you overhear the following responses:

そのお知らせの後,誰かがこう言うのを耳にしました。

As soon as one airline announced its plan for airfare reductions, the rest of the companies followed suit.

ある航空会社が運賃値下げ計画を発表すると、他社もすぐに追従した。

The report topic will be announced at the appropriate time.

レポート課題は適切な時期に告知します。

I couldn't understand the announcement that was just made.

今のアナウンスがよくわからなかったのですが。