Home > Articles > Programming > Java

  • Print
  • + Share This
Like this article? We recommend

A Complete Java Sound API Application

Figure 2 illustrates one of the sample applications that comes bundled with the Java Sound API demo. To run this program yourself, just download the associated files.

Then, run the following command from the download folder:

>java -jar JavaSoundDemo.jar

This command should produce the main application window illustrated in Figure 2.

Figure 2

Figure 2 The sample Java Sound application

Once you see the window in Figure 2, you can start to interact with the application. The application has four configured modes as indicated by the tab controls at the top of the window. The startup mode is Juke Box. On the left hand side of the window underneath the tabs is a list of sound files in different formats. Clicking the Start button plays back the contents of the listed files. Using the slider controls at the bottom of the window, you can modify the pan and gain settings for these pre-recorded sounds.

In using the Juke Box mode, you can get to play around with the playback features and sound formats of the Java Sound API. You might say the Juke Box mode is a kind of 21st-century "Hello World"!

So, what about recording audio? Clicking the second tab (Capture/Playback) at the top of Figure 2 moves the application into the mode illustrated in Figure 3. As mentioned earlier, this looks extremely complicated, but it's not really. The contents of Figure 3 represent a useful learning opportunity, so let's break it down into manageable chunks.

Figure 3

Figure 3 The Capture/Playback window

The box with the black background is called a sampling panel. This panel contains a graphical representation of the sound sample. When you play a sound, the sampling panel in Figure 3 provides visual feedback in the form of a vertical bar that moves from left to right. You can use the buttons above the sampling panel to control the playback as well as the recording. The buttons provide four options: Play (simple enough, just play a recording), Record (acquire a sound source and record it to memory), Pause a playback, and Load (to load a pre-recorded sample file).

If you opt to record a sound sample, you can then save it to disk by typing a name into the File to Save control and clicking on the required file format button below it.

So, that's the right hand side of Figure 3, but what about those complicated-looking buttons on the left? The three buttons—linear, ulaw, and mlaw—all relate to the encoding of the sound sample. Encoding is basically how the sound sample is transferred from the analog domain into the magical digital world. One of the interesting aspects of analog-to-digital conversion (and its opposite, digital to analog) is the fact that it is essentially impossible to exactly match sound in these two domains. The difference may well be impossible to detect by most of us, but it is a well-known effect called quantization error.

The buttons below the encoding button group relate to the sampling interval. The rule of thumb is that the larger the number of samples taken, the better is the reproduction. This is why the default mode in Figure 3 is set to 44,100 samples per second.

Underneath the sample rate buttons, we find the number of bits in a sample word. Again, the higher this is the better because it allows the digital representation to more closely resemble the analogue sample. This is why the default is 16 rather than 8.

Next up, we have the signed and unsigned buttons. The use of signed numbers allows for positive and negative sample values. We're almost done! The choice of little endian versus big endian relates to the manner in which multibyte integer values are ordered. Little endian uses one ordering and big endian uses another. The default is big endian because this is the Java default.

The last button pair in Figure 3 is the mono stereo setting. The default is stereo in order to produce a better sound by using two speakers as opposed to just one speaker.

It's useful to play around with the controls in Figure 3 to see how they affect the sound produced by the program. If you want to record some sound, you'll need some sort of microphone. I used my VoIP phone for this, but many modern computers include a built-in microphone as standard.

The remaining tabs in Figure 3 allow you to use the synthesis options that the Sound API provides. This includes a comprehensive implementation of MIDI synthesis as well as pre-configured tunes. Figure 4 illustrates the MIDI synthesizer.

Figure 4

Figure 4 The MIDI synthesizer

The graphical display at the top of Figure 4 simulates a piano, and you can see it provides a dizzying array of options for the budding musician. It's worth remembering that the code that produces Figure 2 through 4 is just some pretty straightforward Java.

As I've often remarked in the past in relation to design patterns, a small amount of Java can supply you with a disproportionately large amount of power. This is certainly the case here! So, when you've sated your appetite for nifty synthesized tunes, we can look at the last tab option from Figure 2—namely the Groove box as illustrated in Figure 5.

Figure 5

Figure 5 The Groove box

As with the MIDI synthesizer in Figure 4, the Groove box in Figure 5 allows you to combine a rich assortment of sounds to create your required tunes. Who needs iTunes with all this?

Accessing the Sample Code

The sample code for the application described here can be downloaded from Sun Microsystems. Just click on the option called Demo Download and follow the on-screen instructions.

Running the Program as an Applet

If you want to run the program as an applet, you'll have to modify the security settings. Just click on the Options button in Figure 2 and the directions for applet use are displayed.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020