Experiment 5: Introduction to Sound

Introduction: 
This lab was conducted in order to analyze the sound waves produced by a human voice and a tuning fork. A microphone was used to gather the information.

Data:
#1 graph

Close up of the voice graph.

#1h graph

Graph given by LoggerPro using a human voice and recording for 0.3 seconds.

#2 graph

Graph given by a second voice by LoggerPro that is recorded for 0.03 seconds. 

#3 graph

Graph given by LoggerPro using a 440 Hz tuning fork and recording for 0.03 seconds. The graph is sinusoidal.

Results:

Voice graph #1

1) The wave is a periodic function. The graph shows repetition after some time.

2) About 5 waves are shown in this sample of 0.03 seconds. We determined this number by counting the number of maximum points present in the sample.

3) The probe collected data for about the time it takes to blink. 

4) The period of these waves is 0.008 seconds. We determined this by finding the amount of time it took to repeat the maximum points.

5) The frequency of the wave is 125 Hz. We determined this by using the equation f= 1/T where T is the period. 

6) The wavelength is 2.74 meters. The length of the sound waves is about as long as a table.

7) The amplitude of the waves is 2 arbitrary units of sound pressure. We determined the amplitude by subtracting the highest point from the lowest point.

8) The graph would likely be very cramped and not easily interpreted because the sample size would be large and the motion of the waves is very erratic.

Voice graph #1h

Comparison between the second voice graph and the first voice graph. Sample sizes are both 0.03 seconds.

Tuning fork

Comparison between the voice graphs and the tuning fork graphs. Sample sizes were both 0.03 seconds.

If we were to test our data for the same tuning fork at a quieter sound level, we would expect to have a smaller wave amplitude due to there being less pressure exerted by the tuning fork to the surrounding medium. We would produce this sound by hitting the tuning fork softer against a surface. By doing so, the amount of force exerted on the tuning fork by the surface will be less, which will decrease the intensity of the sound waves.