Introduction to Sound

Introduction to Sound 

Objective:

 The objective in this lab was to analyze the periodicity of human sounds as well as the wave properties of  a human voice.

Equipment: 

Laptop

Logger Pro

Microphone

Procedure:

 To perform this lab a microphone was set up with logger pro. one persons voice was recorded saying "AAAAAA" and then analyzed for period and frequency. This was then repeated with a different subject. Finally the experiment was performed using a tuning fork.

First Voice:

Although this wave is not pretty it can be seen that it is periodic. It appears to show 4 waves based on a chosen point that represents the repetition. This sample's length can be likened to the blink of an eye. In order to determine the period the time between two "peaks" was measured by picking two pints where the wave appears to start over resulting in a period 0.0063 and a frequency of 158.7 hz based on f= 1/T . Using V= λf and 340 m/s as the speed of sound gives  a wave length of 2.142 m.

2nd Voice:

this voice showed a period of 0.0083 s and a frequency of 120.5 Hz and a wave length of 2.822 m .

There is a clear difference in the amplitude of the two voices.

Tuning Fork ( 570 Hz) :

the periodicity of these waves is much clearer than with the earlier ones. The second wave has a higher amplitude because it was struck on a harder surface. Analyzing the period of these waves resulted in a frequency of 256.41 Hz and the tuning fork is supposed to be 570 Hz, this shows that the equipment is quite accurate in its measurements. The shape of this graph when compared to the human voice shows that the human voice does not emit a constant sound.