Text: Then there are the baby monitors, arguably a necessity if you live in a big house and can't hear the baby crying in her room--and also a necessity if you're interested in intercepting police transmissions--but is the Child View Monitor and Television, for $149.
Entailment: It is possible to not hear a baby crying if you live in a big house.
Contradiction: Baby monitors would be a good idea, but there are none in existence currently.