How long does an echo last in a big room?

The duration of an echo in a big room can vary significantly based on factors like the room's size, shape, and the materials of its surfaces. Generally, an echo can last from a fraction of a second to several seconds. In large, open spaces with hard surfaces, echoes may persist longer as sound waves bounce off the walls. In contrast, softer materials or furnishings can absorb sound and shorten the echo's duration.