Our original experiment design was to waterproof a speaker and have it play three different pitched sounds. These sounds would be picked up by a waterproofed microphone from four different distances away from the speaker. When figuring out a way to successfully waterproof a speaker, we came across a brilliant idea. We could use a battery powered speakers and a portable CD player. We were able to put both the speakers and cd player in a medium size tupperware container. This design was simple, and it worked. Getting closer to the date which were going to run our experiment, we found out some bad news. The D.E.E.P. waterproof microphone could not be found anywhere. Instead we were given alternative microphones which we waterproofed ourselves. Waterproofing was not that difficult. When trying to hook the microphone to our recorder, we realized it did not work. We went through three recorders, none of which worked with the microphone. We realized that we did not need the microphone, and so we decided to waterproof our recorder instead. The recorder worked just fine underwater. But since there was so much noise in the pool at Long Beach, it did not pick up any of our sounds. Luckily we got together after the trip and used a bath tub, which worked great. If we could redesign our experiment, we would look at the possible error before hand, and save time.
Originally we planned to record the three sounds from four different distances; 1 foot, 2 feet, 4 feet and 6 feet. Since we used a bath tub we were not able to run the experiment from 6 feet, instead we ran if from 1,2,3 and 4 feet.
Our Results: (view tables of results)
High Pitch Sound:
The average mean for the high pitch sound was 66.33 dB. At two feet away from the speaker the results were louder then at 1 feet, 3 feet and 4 feet away from the speaker.
Medium Pitch Sound:
The results for the medium pitch sound were much higher. The average mean was 69 dB. At three feet away from the speaker the results were the loudest, out of the medium pitch sound results. This could be a result of error. At four feet we only had data for one trial.
Low Pitch Sound:
The average mean for the low pitch sound was 70.84 dB. At two feet away from the speaker the results were the lowest. Between two feet and three feet there was a 10.66 increase in decibels. This is a possible result of error.
From looking at the results, we can say that the low pitch sound was best heard underwater. With in the low pitch sound, the pitch was best heard at three feet away from the speaker.
the percent error was on the lower side, all the low pitch sound results
of the other three distance's averages. The medium
results were very similar to the high pitch sound results. The results
for the low pitch sound showed a very small variation between the results
and medium pitch sounds. The mean’s of the low pitch sound were
slightly higher, but this is not not enough of a difference to assume
that the lower
pitch sound was best heard.
When looking at a graph of the sounds, one would expect an obvious change in slope. Our results do not show this. The reason for this being that the distances were not far enough from the speaker to affect how well the sounds were heard.
If we were able to run our experiment from farther distances, our results would probably differ drastically. If we could go at least four or five feet farther away, our results would show which sound was really heard best. If we did rely on our results, which support the low pitch sound, we could assume that the low pith would best be heard from farther away. Once again though, this information does not vary enough to fully support this prediction. We used a bath tub so we were unable to go farther than four feet. We were not able to use the pool because it was too loud.
The main reason we did not have any data from the Long Beach trip, was because the pool was too loud. Our recorder picked up people breathing instead of our three sounds. When we used the bath tub our error was lower. As we were recording the sounds underwater, our recorder still picked up excess sounds. One of these unintentional sounds was the plastic bag moving. The percent error was the lowest in the trials for the low pitch sound. This might also explain why the low pitch sound was best heard. The percent error was the highest in the medium pitch sound, but still the high pitch sound was better heard than the medium pitch. Overall we had minimal error, and it was probably not enough to truly affect our results.