The streets are full of people with cellphones pressed to their ears.
Their other hands are usually employed in covering their other ears, in order to avoid distraction by the background hum of traffic and chatter.
Today’s invention is a flexible, sound-insulating back for one’s cellphone.
In a noisy environment, this cup can be unclipped and placed over the non-listening ear whilst taking a call. The cup has a soft outer ridge which forms a good seal against the skin around one’s ear, when pressed into place, thus freeing-up one of the user’s hands.
The cups could be made in a skin tone to match the user’s own (or moulded into a quirky, Vulcan version).