Look in

https://github.com/m5stack/M5Tough/blob/master/src/utility/M5Button.h

It explains the touch button usage.
-Brent

Look at the M5Unified Speaker example it has full volume and tone control and runs on the Core2

Check out the speak.ino in the new M5Unified library v0.0.5
it will compile with the Core2 or the Tough and produce sound.

There is a M5 speaker class , that can be used to produce tones.

The problem is that while the library works by itself
it is Not compatible
with M5Tough.h or M5Core2.h files.

And yes , there is a problem with the Core2 and Tough speak.ino
the Log file shows a conflict with mclk pin config , when trying to setup the I2S sound
The error is in a higher level M5 system file that was introduced when the Tough was released in the Fall.
Sorry , I dont know how to fix it..

-Brent