The Chafetz Chaim, Avot and Hi-Tech

In Avot 2:1, Rabbi Yehudah Hanasi teaches:

Contemplate three things, and you will not come to the hands of transgression: Know what is above you: a seeing eye, a listening ear, and all your deeds being inscribed in a book.

On this mishnah, a recent post on the Breslov.co.il website writes about Rabbi Yisrael Meir Kagan (the "Chafetz Chaim) as follows:

We marvel about the driverless car, but the car itself was invented in the 1800s. We marvel about wireless smartphones, but both wireless and telephones were developed right before World War I. Technology really got legs in the late 19th century.

The great sage who bore witness to the initial transformation from an industrial world to a digital one was the Chofetz Chaim.

His insights about hi-tech are relevant to this day. According to the Chofetz Chaim, hi-tech is an emuna learning aid. To better internalize the principles of the First Commandment, G-d gave us the telephone.

To better understand how Hashem could actually hear all of our voices all of the time, G-d brought into the world a device that can enable any of us to hear someone talking from thousands of miles away. If we could hear someone speaking lashon hara (slander) the other side of the planet, surely Hashem could hear it as well. If we could talk with more than one person on the phone, and hear voices from people in different cities countries and oceans apart, surely Hashem can hear everyone, everywhere.

Does anyone know where the Chafetz Chaim discussed this topic? I couldn't find it in my old copy of Masechet Avot im Pirushei Rabbi Yisrael Meir HaCohen (1974) under Avot 2:1.