We've seen lots of bone-conduction phones and accessories that change the way we receive calls by skipping the outer ear and sending sound through the skull to the inner ear. But a Japanese firm has become the first to turn the way the microphone works on its head too.

E-Mimi- kun from NS-Elex is the oddly named device in question and it works by listening to the vibrations inside the ear. Apart from the accompanying decoder box, it looks like a slightly larger-than-normal headphone earbud when stuck in the ear.

Bluetooth option

Once in place, e-Mimi-kun deciphers vibrations made when we speak into audio that is then transmitted, either by wire or Bluetooth, to the phone during an outgoing call.

It isn't cheap at ¥40,000 (£175) for the wired version and 50 per cent more for the Bluetooth one. As usual, the company behind 'Good Ear Boy' (honest - that's what the Japanese name means) suggests it be used in noisy environments like building sites.

One possible side-effect, however, is that mumbling nutters everywhere can rejoice now, as they'll blend in with the rest of us once tech like this starts appearing in public places.