Negative decibels? Our discussion of decibels did not mention that they can be negative. On the Redmond, Washington campus of Microsoft is an anechoic chamber that, according to Guinness World Records, is the quietest place in the world. It measures -20.3 decibels. a. What is the relative intensity of a sound measuring –1 decibels? Round your answer to one decimal place. b. What is the relative intensity of a sound measuring –10 decibels? Round your answer to one decimal place. c. What is the relative intensity of Microsoft's anechoic chamber? Round your answer to three decimal places. d. Is it possible for the relative intensity to actually be zero?

The highest frequency sound humans can hear is about 20,000 HzHz. 1. What is the wavelength of sound in air at this frequency? 2. What is the wavelength of the lowest sounds we can hear, about 20 HzHz?

The Wanamaker Pipe Organ in Macy's Center City department store in Philadelphia is the largest working pipe organ in the world. The organ occupies a seven- story hall, and has the longest pipe length of 9.75 m that occupies four floors and can be used as either an open or a closed pipe. Assume that the speed of sound is 345 m/s. a. Calculate the lowest fundamental frequency for the Wanamaker Pipe Organ. b. The highest note on an 88-key piano is 4186 Hz. What would be the length of a pipe open on one end that produced this as a fundamental frequency?

8. When you are 5.00 meters from a point source of sound waves you detect an intensity level, B, of 117 dB. The power output of the source is: a. What is the intensity level, ß, that you will detect if you moved to a location that is 10.0 meters from the source? Note your answer should be in dB. b. What is the power output of the source (in Watts)?