Only a few sounds use lip shapes. Most sounds are based on tongue positioning. Compare ‘m’ & ‘n’ to… not making any sound with your lips together or slightly pa

Only a few sounds use lip shapes. Most sounds are based on tongue positioning. Compare ‘m’ & ‘n’ to… not making any sound with your lips together or slightly parted. The only sounds I would be very confident at recovering sounds from images for ‘th’, ‘w’, ‘o’, & indistinguishable voiced/unvoiced pairs like ‘b’/‘p’ or ‘v’/‘f’. Basically, the sounds a ventriloquist has to cheat.