 In particular, on this tour Keane emphasized the percussive nature of the piano, since they had discovered during the U2 shows that the piano sound echoed off the back walls of arenas, giving it a delayed, doubling sound effect that further made the group's sound dense.Thus for the Under the Iron Sea tour, the group's sound crew added a delay element into the processing of the piano mic pickups, thereby reproducing that arena effect in the band's smaller-sized venues when headlining.Since Chaplin entered rehabilitation on 22 August 2006 it was suggested the tour should not be continued until early 2007.