The software behind the listening. Accents and background noise change how well it hears you, and most of them let you go back, review and delete what was kept.
The drawing that proves the sentence above. It is the same card that is in the book.
Think of it as
the mind behind the butler's ears.
For example
You ask for the weather and get it. Your grandmother asks the same thing and it mishears her twice, because it has heard fewer voices like hers.
This is one card out of 275.
The hundred words you meet most are free — the whole set, animated, in one file that works with no internet.
Volume 1 has all 275 in fifteen chapters, with Staying Safe the largest chapter on purpose.