The effect produced when sound is reflected back is known as what?

More Questions:

What floor number is often skipped in Chinese buildings, as the thirteenth is in the West?

What do climbers rub on their hands for extra grip?

In which sport is there a time period called a "chukka"?

Thor is the son of which Norse god?

What is the capital of Catalonia?

What city dug the first subway?

What two US states border Mexico's largest state, Chihuahua?

Who won a Nobel Prize for discovering Prions?

A skulk is a group of which animals?

What name is given to someone who keeps "apis mellifera"?

What is 400 in Roman numerals?

What movie gave us the tagline "The first casualty of war is innocence"?

What disappeared from the town of South Park, forcing Randy to relocate his family to a refugee camp in California?

Who is the lead guitarist in the band "The Who"?

In 1926, Admiral Richard Byrd made the first flight over which pole?