For the biggest football event of the year, Super Bowl XXXV, much of the experience for fans who are heading to Raymond James Stadium will be how the game sounds. Whenever people go to large assembly spaces, acoustics is something they notice. Marsh says the design of a particular stadium and how noisy the crowd gets can make a big difference in how fans in the stands will experience this year's SuperBowl. Marsh says an advantage of the Raymond James Stadium is that it is open air, which cuts down on reverberations that can interfere with one's ability to understand announcements and other speech produced by the sound system.
Reverberation is when sound persists even after the source of the sound has stopped.
Marsh and his colleagues use reverberation time as one means of determining acceptable acoustics for a particular space. Unlike open-air stadiums, Marsh says, enclosed stadiums often have reverberation times on the order of 10 seconds, which makes speech difficult to understand. However, echoes caused by sound reflected off distant surfaces must still be dealt with. Designers such as Marsh try to minimize the affects of echoes and reverberation by shaping and treating building surfaces. Sound reflects off hard, smooth objects the way light reflects off a mirror.