0.7 Jbs2030-a pure sinusoidal tone

Table of contents

• Preface
  • Viewing tip
    • Listings
• General background information
  • A square wave
    • An audio graph of a square wave
  • A pure sinusoidal tone
    • The difference explained
    • An audio graph of a sinusoid
• Discussion and sample code
  • Three classes are unchanged
  • The class named MusicComposer06
  • The class named ToneMono
    • Beginning of the class named ToneMono
    • Beginning of the getMelody method
    • Required audio data format
      • Monaural, channels = 1
      • Stereo, channels = 2
    • Decomposing a short into two bytes using ByteBuffer
    • Instantiate and prepare a ByteBuffer object
    • Why use a ByteBuffer object?
    • Compute and deposit audio samples in melody array
• Run the program
• Miscellaneous
• Complete program listings

Preface

This module is part of a collection titled Accessible Objected-Oriented Programming Concepts for Blind Students using Java . It explains how to write a program that creates an audio output consistingof a pure sinusoidal tone at 1000 Hz in a format that is accessible to blind students. It also explains how to use the ByteBuffer class to populate an array of bytes with data of type short .

Viewing tip

I recommend that you open another copy of this module in a separate browser window and use the following links to easily find the listings while you are reading about them.

Listings

• Listing 1 . Beginning of the class named ToneMono.
• Listing 2 . Beginning of the getMelody method.
• Listing 3 . Instantiate and prepare a ByteBuffer object.
• Listing 4 . Compute and deposit audio samples in melody array.
• Listing 5 . The class named AudioFormatParameters01.
• Listing 6 . The class named AudioPlayOrFile01.
• Listing 7 . The class named AudioSignalGenerator02.
• Listing 8 . The class named MusicComposer06.
• Listing 9 . The class named ToneMono.

General background information

A square wave

In an earlier module, we wrote a program that causes the diaphragms on computer speakers to move back and forth by creating audio data based on asquare wave. Click SquareWave to hear a sample of a 1000 Hz square wave. (You should be able to play the audio file with any standard media player that can handle the AU file type. In caseyou are on the OpenStax site and you are unable to download the audio file, click the Legacy Site link at the top of this page to switch over to the same module on the Legacy site. You should be able todownload the audio file from there.)

An audio graph of a square wave

I explained the concept of an audio graph in earlier modules. Click AudioGraphSquareWave to hear an audio representation of the graph of a square wave.

A pure sinusoidal tone

In this module, we will write a program that causes the diaphragms on computer speakers to move back and forth by creating audio data based on asinusoidal function. Click ToneMono to hear a sample of a 1000 Hz sinusoidal function. Compare this sound with the sound ofa SquareWave with the same fundamental frequency.