Reverberation can cause echoes . The length of this sound decay , or reverberation time , receives special consideration in the architectural design of large chambers , which need to have specific reverberation times to achieve optimum performance for their intended activity . In comparison to a distinct echo that is 50 to 100 ms after the initial sound , reverberation is many thousands of echoes that arrive in very quick succession ( .01 â `` 1 ms between echoes ) .