Heard is a funtime-shifting app that lets you record audio in the immediate past. It uses the same princicple as TiVO and other time shift TV recording technology.
With HEARD installed on your iPhone, you have a powerful time-shifting app that lets you customize how far back you want to go so you can grab that otherwise missed audio. The HEARD app runs silently (and seamlessly) in the background and ‒ with a simple tap ‒ the instructions / driving directions / jokes / stories / first words / laughter you would have previously missed are now saved and stored on your iPhone.
The app’s free version will only get you 12 seconds of the past, but you can get the premium app to get the last five minutes of audio. Just make sure you have permission to record audio from all present - it’s not always legal if you’re not the NSA. The app also comes with share features so you can Facebook and email all of those historical soundbites.