How do echoes in a normal room affect the quality of the sounds that we hear?

For a distinct echo to take place, the minimum distance between the source of sound and the reflector must be 17.2 meters at a particular temperature in the air. The persistence of sound is 0.1 seconds. Since the distance between the walls and ceilings of a small room from the source of sound is less than 17.2 meters, the reflected sound is produced 0.1 second before the original sound. Due to this, a prolonged sound is heard in place of an echo which is called reverberation. Due to multiple reflections we hear same sound many times.so this persistence of sound creates a problem in listening words separately. The sound we hear comes many no of times and this is how our brain is confused to recognize the sound.