Disclosed are a display apparatus and a method of controlling the display apparatus. The display apparatus includes: a signal receiver configured to receive a broadcasting signal; a display configured to display an image based on the received broadcasting signal; a sound receiver configured to receive a sound spoken by a user; a first sound recognizer configured to be supplied with power when the display apparatus is in a standby mode, and determine whether the received sound is a reserved word candidate having a high probability of corresponding to a reserved word; a second sound recognizer configured to be supplied with power when the received sound is determined as the reserved word candidate and to determine whether the received sound is the reserved word; and a controller configured to control the preset operation to be performed when the received sound is determined as the reserved word.