The Museum Sound Case Challenge

A sound case for the Sound Makers gallery

At the Children's Museum Sound Makers gallery, visitors press a switch to hear a short musical note. The museum team wanted a small sound case that could make the note easy to hear without exposing its wires. Their model used a battery pack, a switch, wires, and a buzzer inside a case. When the switch was closed, electrical energy traveled through the wires to the buzzer. A part of the buzzer vibrated and made nearby air vibrate, producing sound.

The team compared two cases. Case A had cardboard walls. Case B had thin wood walls. Each case had the same buzzer, battery pack, switch, wire length, sound opening, and starting battery condition. The team tested both cases in the same room. They changed the case material and measured the farthest distance at which a listener could hear the note. They also recorded how long the buzzer worked before the sound stopped.

The gallery's requirements were that a visitor hear the note from at least 3 meters away and that the buzzer work for at least 30 seconds. The notes list four trials for each case. Case A's distances were 3, 2, 3, and 2 meters. Its operating times were 42, 39, 41, and 40 seconds. Case B's distances were 4, 4, 3, and 4 meters. Its operating times were 36, 35, 37, and 36 seconds.

After the tests, the team noticed that the wood case met the distance requirement in each trial and the time requirement in each trial. The cardboard case met the time requirement in each trial, but its sound reached 3 meters in only two trials. The team wanted more evidence before choosing a final case. They also considered how the case opening could let sound move out toward visitors.