Even leads for monitoring brain activity don't do that stuff. And they are monitoring literally mV. Leads and contact patches are often made of silver to capture that stuff too, and they have actual reasons to use silver.

> And they are monitoring literally mV.

Far lower than that. Most EEGs at the scalp are in the 10-100 µV range.

For medical devices, they're profitable by being based on reality instead of just bullshit.

This company is also guilty of some silly cable marketing: https://www.audiodesign.co.uk/styled-26/styled-21/index.html