If I was to be paid a tenner for hearing that phrase (along with 'deaf and mute') since the beginning of the year, I tell you that I'll become a thousandairesS.. o joke!
Seeing that many people are not able or fail to connect the necessary dots between hearing and speaking ab nitio, I have had to ask them to imagine what it means to speak the way they do. Did they imagine it into existence? How do they know the 'I' in words should be pronounced as an 'ee' or an 'ai' without looking at a dictionary or hearing someone say it.
Using the word 'dumb' is a no-no. Dumb in today's speak means 'stupid' and deaf people are certainly not that! I have come across the usage of 'speech-impaired' as a politically correct term but I do not think that it is accurate. Simply because many deaf people CHOOSE not to speak or prefer to use sign language. Another word 'unvoiced' brings up some varying reactions as is the word 'silent'.
The word 'deaf' is enough and acceptable by for many deaf. There is no need to waste ink or carbon dioxide to add '...and dumb'. Really.