When operating a smartphone, three of the five senses are used: touch (manipulating the screen), hearing (listening to music or a show — or just participating in that old-fashioned activity known as a phone call) and sight (viewing photos or video on the high-resolution display).

The other two senses — taste and smell — may not come into play, but Tokyo-based Scentee Inc. wants to change that. It is releasing a gadget to the market next month that will make smell a part of the smartphone experience.

The attachment, also called the Scentee, emits a scent in accordance with how the phone is being used. It is believed to be the world's first such device for smartphones.