I suggest the establishment of an international set of gestures to convey the most common phrases such as:
"Do you come here often?" (form U with upturned hand + walk with the index and long fingers in the air several times + point towards floor)
"Your place or mine?" (clasp hands as in prayer while on knees + place them under the head tilted sideways + point index finger alternately at observer and self)
"Does your 'no' really mean 'no' or can it mean 'yes'?" (make windshield wiper motion with index finger + raise shoulders and eyebrows + stick long finger deep into mouth + peel an imaginary banana).

Not only would the vocal cords be spared, but a new dance craze might be born from long conversations.