It’s a well-known belief that deaf people can read lips and that by doing so they are compensated for their lack of hearing. This is only somewhat true in that although they do read lips it doesn’t mean that they receive all the information.

With lip reading one can “read” 50%, another 30% is not understandable but can be understood by the context, and 20% simply gets lost. To be able to better comprehend this all we have to do is stand in front of a mirror and move our lips without speaking while pronouncing the words “mama” and “papa”.
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Is there a difference? No, because there isn’t one.

That’s how words like “map” “pap” ,”food” and “dude” sound the same. In the first case there is no problem, because there is context. If we say for example: “I’m lost, I need a——- to get home.” One can detect the word map without a doubt. But if someone says: “I’m hungry for some—-“, we don’t know if the person is really hungry or has an outrageous sexual necessity.