Sound that arrives at the eardrum by an indirect route (reflected, for example, from the walls of a concert hall, or emanating from the inside of a kettle drum), and the perceived effect of such sound. Because sound takes time to travel through the air, the same sound can hit the eardrum several times from different secondary sources, effectively enriching the soundΓÇÖs quality and extending its length in time. An echo is an extreme form of reverberation.
