iPhone Life magazine

What the iPhone’s Sound Capabilities Can Do for Your Projects

One of the most overlooked aspects of the iPhone is its ability to playback uncompressed, CD quality audio. Apple has managed to squeeze even more quality and volume out of the tiny speakers on the newer 
iPhone3GS. Also, most people are unaware of the 3D positional sound feature incorporated into the original iPhone and what it actually does. This feature allows the developer to simulate moving sounds and have them play anywhere in three-dimensional space around the listener. For example, if a game developer needs to have a jet fly by the left side of the player, they can use the positional sound feature to place it there. Other devices can do this, but Apple makes it a lot easier for the developer. This aspect of iPhone audio development is in its infancy; we can look forward to even more innovative products using this feature.

Graphics effects and animation tend to hog the spotlight, and sound is often given much less attention. However, rich music, sound, and voice content are great ways to enhance your games and other apps. Although the laws of physics prevent us from hearing deep bass tones from the iPhone’s built-in speakers, we can certainly enjoy the rest of the sound spectrum and relish in the rich mid and high frequencies!

Make your apps more fun


With a little creativity, an application can be brought to life with audio. Traditionally, games have been the only apps to get the sonic treatment, but we are now seeing that other apps can be equally enhanced with audio. Having a sonic signature for a product or company logo is a good place to start. This can increase brand strength and improve customer satisfaction. Something as drab as a notetaking app can be made fun with the creative use of music, sound, and voice.


Hiring a professional audio producer is one way to do this, but you can also take a do-it-yourself approach. There are plenty of free or inexpensive options available to developers, including online sound effect libraries like the popular SoundSnap (soundsnap.com), which let’s you browse their library and download five free sounds every month. Another great site is FreeSound (freesound.org), which also has a vast library of sounds you can browse. Sites like these allow you to preview the sound before downloading it to your computer. Keep in mind that these sounds may have been downloaded and used elsewhere, so if originality is important, it’s probably best to hire an audio professional to create a unique audio track.

Finally, if you have the time and interest, you can make the free sounds you’ve downloaded unique by altering them using one of the free audio programs available on the Web. If you’re interested in this, check out one of the following programs.

The following are a couple of apps that make good use of the iPhone’s potential. The first is a game I helped develop. The second is an app developed for bird lovers. Both of these demonstrate how developers can use quality audio to enhance the user’s experience and make their app more compelling.

Audacity (audacity.sourceforge.net); available for Mac OS X, Windows, GNU/Linux. Reaper (reaper.fm); Mac OS X and Windows. Traverso (traverso-daw.org): Mac OS X, Windows, GNU/Linux.

Sound can make a huge difference in the quality and enjoyment of your app. It truly enhances the users’ experience and could, quite possibly, increase sales.

Gravity Sling

Gravity SlingGravity Sling (free, riptidegames.com) (above, top) is an inertia-based puzzle game set in deep space. The objective is to get the astronaut back to the ship by using the planets gravitational pull. The audio portion of this game consists of swirling cosmic textures and a futuristic music track that dissolves into an ambient soundscape. Although the iPhone can play only one compressed audio file (mp3) at a time, it can layer several uncompressed WAV or AIFF files. Creatively combining music and ambience and mixing them into a single mp3 can help to keep down the size of an app.


The Peterson Field Guide to Backyard Birds

Peterson's GuidePeterson's GuideThe Peterson Field Guide to Backyard Birds ($2.99; 
wildtones.com) (above, middle and bottom) is a guide containing illustrations and information about hundreds of bird species. The guide lets you search for birds in your area by map or Zip Code, but the great thing about this app is its creative use of audio. You can hear the sounds of each birdcall. The guide also has quizzes that test to see if you can identify these birdcalls. Although the app takes up a whopping 92 MB, it is a fun way to find out more about the birds in your area.