Eli5: How do automated services on phones know what buttons you’re pressing?

449 views

I was just refilling a prescription on the automated line and the thought just dawned on me. How do they know what buttons I’m pressing? Sorry if this is really dumb. I understand next to nothing about technology. Thanks

In: 66

18 Answers

Anonymous 0 Comments

Each button sends a different, unique tone to the other tone. Both phones know which tone each number sends.

You are viewing 1 out of 18 answers, click here to view all answers.