Does it matter if you have a 2.4GHz phone hooked up to the same line as a DECT 6.0GHz phone?

Question

Will the 2.4GHZ negate the security of the line that the DECT 6.0GHz is supposed to provide? Does that all matter whether the phone is in use? Can someone still break in to your line with a 2.4GHz if nobody is using the phone?

Answer 1

2.4 and 6 GHZ refer to the carrier freq. used for the phones.
Obviously, if you have no conversations using the 2.4 GHz phone, nobody can listen to them.
However, if nobody uses it, why do you still have it?