Listener

Listener is an achievement in Halo 3: ODST and Halo: The Master Chief Collection. It is awarded for finding the first Audio Log in the campaign. It is worth 5 Gamerscore.

In the original game, the achievement is represented by a red square with audio lines going across it, with the number 1 in the lower-right corner, and a picture of the Superintendent looking angry. In the Master Chief Collection it is represented by a sequence of images from Sadie's Story, overlaid with an image of the Superintendent.

Location
The achievement is awarded when the player unlocks their first terminal, regardless of which terminal in the hub that is. For terminal locations, see here.