Inscrutable !

Scientists in Japan have created a smoke detector for deaf people which warns them with the smell of wasabi. Boffins from Shiga University of Medical Science say they needed to come up with a way of waking deaf people if they were asleep.

The problem was that 50 percent of fire victims in Japan are elderly and often have poor hearing - meaning ringing alarms don't wake them. Professor Makoto Imai's design uses a synthesised version of wasabi which is sprayed into the air created the pungent odour. This is said to wake most sleeping people within two and a half minutes… and give them a uncontrollable craving for sushi.

Ref:

The British demanded one that smells like fish and chips, the Americans wanted one that smells like Big Macs..... Mexico wanted the chilli con carne....