In the past, many beaches in Japan were well-known as singing beaches. However,
within the last 50 years most of these beaches have lost their singing properties;
either the beaches themselves have been destroyed by construction work, or the
sand has been affected by sea water pollution. This is common throughout the
world, especially in the advanced countries. If sea-water is contaminated by
soil, dust, oil, detergent, or other miscellaneous materials, the sands stop
singing. In other words, the sound-producing property of singing sand on the
beach shows the purity of the sea-water.