2 moniters??

just a question for anyone with two bubs close in age...do two baby moniters interfear with one another?
DS still wakes thru the night sometimes and is at the other end of the house and bub will be in our room at first so i want to hear her during the day when im in the rest of the house so i need to have two still.
we just have the fisher price one...cant remember the name but its only just over a year old but would i get the same brand or a different one.
Thanks in advance if anyone has any advice.

I have 2 different monitors, one for each of the girls rooms. We have never had a problem with interference.

My girls are close in age...neither use a monitor now, but when they were younger i set the 2 monitors on separate channels.