Sound waves that reach the listener after being reflected from one or more surfaces.
"I RECENTLY SENT YOU A RECORDING FOUND IN MY PARENT'S BELONGINGS AFTER THEIR DEATHS THAT WAS DATED 1945. THE RECORDING WAS MADE IN NEW YORK CITY BY A 19 YEAR OLD YOUNG MAN (MY FATHER) TO SEND TO HIS SWEETHEART (MY MOTHER) BEFORE HE WAS SHIPPED OVERSEAS TO OKINAWA DURING WORLD WAR II. HE WAS IN OKINAWA FOR TWO YEARS (ONE YEAR DURING THE BATTLES ..."