Experiment 5: Introduction to Sound

The purpose of this lab was to observe the properties of sound waves using a human voice and a tuning fork.

We used:
- LabPro
- Microphone
- Brave student
- Tuning fork

PART ONE:
A brave student showed off his vocal skills by saying "AAAAAAAHHHHHH" smoothly into the microphone for 0.03 seconds. We recorded their beautiful voice and we saved the graph on LoggerPro. Below is the graph we obtained.

Below are the answers to the questions about the sound wave obtained.
a) The wave is periodic because although it is not a perfect sinusoidal wave, it has sinusoidal wave properties that repeat it self in a periodic manner.
b) There are about 4.8 waves in this sample. I determined it by counting the number of times the highest wave in the period appeared.
c)We recorded the sound for 0.03 seconds. This is similar to the amount of time that the brain takes to recognize a sound.
d)The period of this wave is about 0.00623 seconds. This is the time that we recorded the waves for, 0.03 sec, divided by the number of waves during that time, 4.8.
e)The frequency is 160 Hz. This is 1/T, where T is the period of the wave.
f) The wave length is lambda=v/f. This is equal to (340 m/s)/(160 Hz)= 2.125 m. This is about the distance from Professor Mason to the first row of desks in class when he is lecturing.
g)The amplitude is 1.543 arbitrary units. This was determined by the graph.
h)If we had recorded for 0.30 seconds, we would have a lower arbitrary amplitude, but besides that nothing else would change because the period of the wave is not changing.

The graph below shows how amplitude would change because it is an arbritary value if we recorded for 10 times longer.

PART TWO:

The individual wave patterns are similar because although they are not perfect sinusoidal waves, they are periodic. This wave has about 4.5 waves in 0.03 seconds. This means the frequency for this wave is   150 Hz. The period for each wave is about 0.0067 sec. The amplitude of this wave is 1.512 arbitrary units. The wavelength of this wave is 2.27 meters. The waves are similar in value but the first wave was a lot more smoother.

PART THREE:

Compared to the wave that was produced by a human's voice, the wave that was produced by the tuning fork is perfectly sinusoidal. It is much smoother and has a clear amplitude and frequency. There were 13 waves in 0.03 seconds. The period is 0.0023 seconds. The frequency was 433 Hz and the wavelength was 0.785 meters.


PART FOUR:

To produce a softer wave, we banged the tuning fork on a softer surface, such as the bottom of a shoe. What changed in this wave was that the amplitude of the wave was higher and that there were less waves produced in 0.03 seconds.