ExpEYES/C2/Characteristics-of-Sound-Waves/English

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Visual Cue Narration
Slide Number 1

Title Slide

Hello everyone.

Welcome to this tutorial on Characteristics of Sound Waves.

Slide Number 2+3

Learning Objectives

  • How to generate a sound wave
  • Frequency response of a sound source
  • How to calculate velocity of sound
  • Interference & Beats of sound waves
  • Forced oscillations of sound source

Show

  • Xmgrace plots
  • Fourier Transforms
  • Circuit diagrams
In this tutorial we will learn to demonstrate:
  • How to generate a sound wave
  • Frequency response of a sound source
  • How to calculate velocity of sound
  • Interference and Beats of sound waves
  • Forced oscillations of a sound source.

And Show

  • Xmgrace plots
  • Fourier Transforms and
  • Circuit diagrams for our experiments.
Slide Number 4

System Requirement

  • ExpEYES v 3.1.0
  • Ubuntu Linux OS v 14.10.
Here I am using,
  • ExpEYES version 3.1.0
  • Ubuntu Linux OS version 14.10
Slide Number 5

Pre-requisties

You should be familiar with:

ExpEYES interface.

For relevant tutorials, visit our website.

www.spoken-tutorial.org.

To follow this tutorial, you should be familiar with:

ExpEYES Junior interface.

If not, for relevant tutorials, please visit our website.

Slide Number 6

Definition of Sound.

Sound is a vibration that propagates as audible mechanical wave of pressure & displacement.

It requires a medium to propagate.

Air, water or metal surface.

Let's first begin with definition of Sound.

Sound is a vibration that propagates as an audible mechanical wave of pressure & displacement.

It requires a medium to propagate.

The medium can be air, water or any metal surface.

Slide Number 7

Characteristics of sound

Carry out various experiments to show characteristics of sound waves.

In this tutorial we will carry out various experiments to show characteristics of sound waves.
Slide Number 8

Frequency of sound

Experiment to show frequency of sound.

Let's perform an experiment to show frequency of sound waves.
Show the circuit diagram. In this experiment, ground(GND) is connected to Piezo buzzer(PIEZO).

Piezo buzzer(PIEZO) is connected to SQR1.

Microphone(MIC) is connected to A1.

Here Piezo buzzer(PIEZO) is a source of sound.

This is the circuit diagram.

Let's see the result on the Plot window.
Point to Setting Square waves, set frequency as 3500Hz. On the Plot window, under Setting Square waves, set the frequency as 3500Hz.
Click on SQR1 check box.

Point to SQR1 check box.

Point to the sound wave.

Click on SQR1 check box.

Frequency of SQR1 is set to 3500Hz.

A digitized sound wave is generated.

Move the frequency slider. Move the frequency slider to change the waveform.
Click on SQ1, drag to CH2.

Point to the assigned data.

Point to the square wave.

Click on SQ1 and drag to CH2.

Input data of SQ1 is assigned to CH2.

A square wave is generated.

Drag the mSec/div slider. Drag the mSec/div slider to set in compressions and rarefactions.
Click on CH2, drag to FIT.

Point to voltage and frequency of SQ1.

Click on CH2 and drag to FIT.

Voltage and frequency of SQ1 is displayed on the right-side.

Move the frequency slider. Move the frequency slider to set in sound waves
Point to the sound wave.

Point to the amplitude.

Sound wave produced by the Piezo buzzer is shown in black colour.

Amplitude of the wave changes as Piezo buzzer is moved closer and away from the MIC respectively.

Slide Number 9

Frequency response

Demonstrate frequency response of Piezo buzzer.

Now we will demonstrate frequency response of Piezo buzzer.
Click on EXPERIMENTS button.

Select Experiment list opens, Click on Frequency Response.

On the Plot window click on EXPERIMENTS button.

Select Experiment list opens.

Click on Frequency Response from the list.

Point to two new windows.

Point to the circuit diagram

Two new windows Audio Frequency response Curve and Schematic open.

Schematic window shows, circuit diagram of the experiment.

Point to Audio Frequency response Curve window, click on START button. On the Audio Frequency response Curve window click on START button.
Point to Frequency response of the Piezo buzzer.

Point to the amplitude.

Frequency response of the Piezo buzzer is set in.

Frequency response has maximum amplitude at 3700Hz.

Click on Grace button.

Point to the Grace window Frequency response Curve

On the same window click on Grace button.

Grace window opens showing Frequency response Curve

Slide Number 10

Velocity of Sound

Measure velocity of the source of sound.

Now we will measure velocity of the source of sound.
Click on EXPERIMENTS button.

Point to the list.

Click on Velocity of Sound.

On the Plot window click on EXPERIMENTS button.

Select Experiment list opens.

Click on Velocity of Sound from the list.

Point to the new windows.

Point to the circuit diagram on Schematic window.

Two new windows EYES Junior: Velocity of Sound and Schematic open.

Schematic window shows the circuit diagram of the experiment.

Click on Measure Phase button. On EYES Junior: Velocity of Sound window click on Measure Phase button.
Move the Piezo buzzer to different distances. We can obtain different Phase values by changing the distance between MIC and Piezo buzzer.
Click on Measure Phasebutton. Click Measure Phase button to obtain different Phase values.
Slide Number 11

Measure Phase

Various Phase values we will use, 178deg & 106deg to calculate velocity of sound.

From the various Phase values we will use 178deg and 106deg to calculate velocity of sound.
Slide Number 12

Measure Phase We can obtain these values when Piezo is kept close & 2cm away from MIC.

We can obtain these values when Piezo is kept close and 2cm away from the MIC.
Slide Number 13

Note

Ensure that MIC and Piezo buzzer are placed on the same axis.

To obtain accurate results, ensure that MIC and Piezo buzzer are placed on the same axis.
Slide Number 14

Velocity of sound.

v=f *(360 * ∆D/X)

v= 3500(360*2/(178-106)

v=35000cm/sec

v=350m/sec

To calculate the value of velocity of sound,

we have the formula as shown:

Velocity of sound obtained from the experiment is “350m/sec”.

Slide Number 15

Assignment

As an assignment,

  • Calculate the value of wavelength of sound.
  • Formula: λ= v/f.
As an assignment, calculate the value of wavelength of sound.

Formula: λ= v/f.

Slide Number 16

Sound Waves

  • Interference
  • Beats
  • Xmgrace plot
  • Fourier Transform.
Now we will demonstrate:
  • Interference
  • Beats
  • Xmgrace plot and
  • Fourier Transform of the two sources of sound.
Slide Number 17

Grace plots

  • python-imaging-tk
  • grace
  • scipy
  • python-pygrace.
To show Grace plots in the experiments:

Make sure that you have installed

  • python-imaging-tk
  • grace
  • scipy and
  • python-pygrace on your system.
Show the picture. In this experiment we use two Piezo buzzers as source of sound.
Point to the circuit diagram. In this experiment Piezo 1 is connected to SQR1 and ground(GND).

Piezo 2 is connected to SQR2 and ground(GND).

This is the circuit diagram.

Let's see the result on the Plot window.
Set the value of SQR1 as 3500Hz. On the Plot window, set frequency as 3500Hz.
Click on SQR1 and SQR2 check boxes.

Point to the check boxes.

Point to the sound wave.

Click on SQR1 and SQR2 check boxes.

Frequency of SQR1 and SQR2 is set to “3500Hz”.

A digitized sound wave is generated.

Move the frequency slider. Move the frequency slider to change the waveform.
Click on EXPERIMENTS button, Interference of Sound.

Point to EYES: Interference of Sound window.

Click on EXPERIMENTS button and select Interference of Sound.

EYES: Interference of Sound window opens.

Change NS value to 1000. At the bottom of the window, change NS that is number of samples value to 1000.
Click on SQR1, SQR2 check boxes.

Click on START button.

Click on SQR1 and SQR2 check boxes.

Click on START button.

Interference pattern is seen.

Click on Xmgrace button.

Point to the Grace pattern.

Now click on Xmgrace button.

A new window opens with a Grace pattern.

Now we will show Beats pattern.
Click on EXPERIMENTS button, select Interference of Sound.

Point to EYES: Interference of Sound window.

Click on EXPERIMENTS button and select Interference of Sound.

EYES: Interference of Sound window opens.

Click on SQR1 and SQR2check boxes. At the bottom of the window, Click on SQR1 and SQR2 check boxes.
Click onSTART button.

Point to Beats pattern.

Click on START button.

Beats pattern appears.

click on Xmgrace button.

Point to the Grace pattern.

Now click on Xmgrace button.

A new window opens with a Grace pattern.

Click on FFT.

Point to Fourier Transform.

Click on FFT.

A new window opens with Fourier Transform.

Slide Number 19

Fourier Transform

Fourier Transform please visit this webpage.

https://en.wikipedia.org/wiki/Fourier_transform

To know more about Fourier Transform please visit this webpage.

https://en.wikipedia.org/wiki/Fourier_transform.

Slide Number 20

Low Frequency Sound Wave

To show a low frequency sound wave.

Let us perform an experiment to show a low frequency sound wave.

This is the circuit diagram.

Click on EXPERIMENTS button select Interference of Sound.

Point to EYES: Interference of Sound window.

Click on EXPERIMENTS button and select Interference of Sound.

EYES: Interference of Sound window opens.

Set the value of SQR1 to 100, check the box. At the bottom of the window, set the value of SQR1 to 100 and check the box.
Click on START button.

Point to the wave.

Click on START button, a low amplitude wave is displayed.
Click on FFT. Click on FFT to obtain a Grace plot of Fourier Transform.
Let's summarize.
Slide Number 21

Summary

  • How to generate a sound wave
  • Frequency response of a sound source
  • How to calculate velocity of sound
  • Interference and Beat pattern of sound waves
  • Forced oscillations of sound source.
  • Xmgrace plots
  • Fourier Transforms
  • Circuit diagrams
In this tutorials we have learnt to demonstrate:
  • How to generate a sound wave
  • Frequency response of a sound source
  • How to calculate velocity of sound waves
  • Interference and Beat pattern of sound waves
  • Forced oscillations of sound source.

And have shown:

  • Xmgrace plots
  • Fourier Transforms and
  • Circuit diagrams for our experiments.
Slide Number 22

Assignment

1. Capture a sound burst

2. Hint: A bell or a clap can be used as source of sound

As an Assignment,

1. Capture a sound burst

2. Hint: A bell or a clap can be used as source of sound.

This is the circuit diagram.

Slide Number 23

Acknowledgement

Watch the video available at

http://spoken-tutorial.org/What is a Spoken Tutorial.

It summarizes the Spoken Tutorial project.

If you do not have good bandwidth,

you can download and watch it.

* This video summarizes the Spoken Tutorial project
  • If you do not have good bandwidth, you can download and watch it.
Slide Number 24

The Spoken Tutorial Project Team,

Conducts workshops using spoken tutorials.

Gives certificates to those who pass an online test.

For more details, please write to

contact@spoken-tutorial.org

* We conduct workshops using Spoken Tutorials and give certificates.
  • Please contact us.
Slide number 25

Spoken Tutorial Project is a part of the Talk to a Teacher project.

It is supported by the National Mission on Education through ICT,

MHRD, Government of India

More information on this Mission is available at,

http://spoken-tutorial.org/NMEICT-Intro.

The Spoken Tutorial Project is funded by NMEICT, MHRD Government of India.
This tutorial is contributed by Kaushik Datta and Madhuri Ganapathi.

This is Sakina Sidhwa. Thank you for joining.

Contributors and Content Editors

Madhurig, Nancyvarkey