Voice callouts are an aural annunciation issued to the pilot when the aircraft reaches a specific altitude during a decent. If TAWS-B is the active system, the system will issue the aural alert beginning at 500 feet. Otherwise, the altitude height limits can be configured from 500 feet down to 100 feet in 50 foot increments. If a radio altimeter (RA) is installed, voice callout aural annunciations can be configured from 50 feet to 1 foot. Voice callouts are triggered by either the height above the runway threshold or height above the terrain immediately below the aircraft.

When the aircraft is within 5 NM of the airport threshold, the GPS altitude above the threshold is used to initiate the alert. When the aircraft is greater than 5 NM from the runway threshold, voice callouts are initiated using the aircrafts height above the terrain. When the system is using height above the terrain data is derived from the optional radio altimeter. However, if a RA is not installed or has failed, the height above the terrain is derived from the GPS altitude and terrain database.

With the RA installed, regardless of distance from the nearest runway threshold, voice callouts are produced starting at 50 feet and continue down to 1 foot.