1. An imager that operates with a photographing mode determined based on an input from a user, the imager comprising: an image-capturing device that captures a subject image and outputs an image; a memory that stores data defining, for the photographing mode, words frequently used in the photographing mode; a voice detector that detects ambient sound; a voice recognizer that converts the ambient sound to characters in consideration of the data defining the words frequently used in the photographing mode, stored in the memory; and a composer that composes the characters into the image.