How to Disable Voice Control on an X1 TV Remote

I have relatives who are mute.  They are physically unable to speak.  They cannot use Voice Commands on remote controls.  I have speech impediments myself and voice systems cannot understand me when I speak--for example, Alexa, Siri, etc.
I was told by an employee at our local Xfinity store that you cannot disable Voice Control on the X1 Remote Control units that go with the new XG model TV boxes.
Is it true that you cannot disable Voice Control on these new X1 Remote Control units?  That if you are unable to speak, or unwilling to have devices talking to you in your home, you can no longer use a remote control to control your TV? 
Isn't that a violation of at least the spirit of ADA regulations that ensure access to persons with disabilities--in this case those who lack the ability to speak?