What is a WAV File?

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  • Written By: R. Kayne
  • Edited By: O. Wallace
  • Last Modified Date: 13 March 2014
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A waveform audio file, also known as a wave file, or simply WAV after its extension, is a common type of sound file. Microsoft and IBM introduced the format in 1991 for use in the Microsoft Windows 3.1 operating system (OS). Long before digital audio became a staple, computer users were exposed to the WAV file as an embedded sound file that played a chime-like sound at boot up of the Windows operating system.

This file format is based on the Resource Interchange File Format (RIFF), which stores audio files in indexed “chunks” and “sub-chunks.” RIFF is, in turn, based on the earlier Interchange File Format (IFF), established by Electronic Arts in 1985 for use in electronic gaming. Apple’s version, known as Audio Interchange File Format (AIFF), was released in 1988 for Macintosh computers. Due to the common roots of these various audio formats, however, the audio files will play on any computer system, IBM or Apple.

The WAV file had two very big things going for it when introduced. First, it could digitize sounds 100% faithful to the original source because it is a lossless format. “Lossless” means that the file format does not compromise audio quality even when it holds compressed data. Second, the format is very easy to edit and manipulate with software. Luckily for audiophiles, free audio editing software has been available nearly as long as WAV files themselves.


While this format was ideal for sound effects, it had a drawback when it came to music files. One four-minute song could easily consume over 35 megabytes (MB) of space when saved as a WAV. Though the cost of hard drives dropped over the years, the format was still too large for portable players with limited flash memory, which would become ubiquitous by the new millennium. Additionally, these files were not the most practical format to transfer online, especially over slow dial-up connections.

Instead, the compressed MP3 format took the audio stage because songs saved in this format are much smaller. The MP3 format is a lossy format, however, which means the smaller file size does have some loss of audio quality. While the MP3 format is a good fit for portable players, many people continue to store their main digital libraries as WAV files. By doing so, the file can be used as a master to create other types of audio files (including MP3s), while remaining preserved for direct listening or burning to compact disc (CD).

Today, the WAV file format is still widely used to archive music files in a lossless format where space is not an issue. Some CD and DVD players can also read these files when they are saved directly to a disc. More often, software that burns the files to CD will convert them in the process to the Compact Disk Audio (.cda) format, making the audio CD compatible with all players.


Discuss this Article

Post 17

I would like to record telephone messages to a cd or memory stick. I have the messages on my landline phone. I am not technically competent, so if you have a way I would appreciate some step by step instructions.

Post 16

Editing or cutting the wav file I recorded on the flash memory voice recorder makes it bigger!

Is there a way that half a wav file becomes smaller in size, not bigger?

Post 14

When you convert an MP3 to WAV, if it's just essentially the MP3 info, why is the file so much bigger?

Post 13

Well done birdboy. excellent. there was some that i thought i understood but now i know fully!

Post 12

Thanks for explaining what is wave file. actually i m doing my project in announcement system based on arm. Could you please tell where i can get more detailed about this so that i can start my programming.

Post 11

I am currently recording radio programs in a computer using a radio card. I actually need to capture various advertisements which are broadcasts within each program. The recorded programs are in WAV format.

Can you please recommend a software that I could use to locate selected advertisements in the recorded programs and save them in MP3 format. As you may have guessed I am not too IT-literate. Thanks in advance.

Post 10

Excellent explanation. Thanks. --Reader in toronto

Post 9

I am converting some of my records. Yes I said records to my computer to eventually save them to a CD. I know the 3 formats are wav. oog. and mp3. Which format should I use to burn to CD's?

Post 8

In response to anon28062, it is not a true statement to say you cannot convert an mp3 to wav and it is not pointless if you are dealing with something that can only handle a wav format. As expected quality will be the same as the mp3, and re-sampling the mp3 with a high quality wav setting will not yield better results as indicated you cannot put back data that was removed, but you can change formats which I think is what anon27459 wanted to know.

Post 7

To 27459, no you cannot convert .mp3 to .wav ... or rather it's pointless as it remains an mp3 file essentially, with a .wav extension.

Waves are lossless files... they contain more data than MP3s. So you can take a wave and convert it to mp3, and in the process it loses some data. But you can't take a .mp3 and convert it to .wav, cause it would have to put data BACK that is not there.

Kinda like, you can take a tree branch and whittle it down into a small stick, but you can't whittle the stick UP into a branch. ;)

Post 6

Do you need a license to make new software that decodes (new codecs) for WAV files? Is it covered by a patent? I know you do for MP3s.. I'd appreciate any help! Thanks!

Post 5

is there anyway to convert mp3 to wav?

Post 4

For those who want to know more, I'll add a few lines about what .wav and .mp3 files really are. MP3 is a codec (codec = coder+decoder). It is named MP3 because it's part 3 of the MPEG1 suite of codecs. It is specifically designed for audio files.

Next, a codec's job is to code(encode) a raw file with data in order to compress it but retain quality and then to play it back the codec must decode the result.

Now, the 'encoder' part of the codec has (very broadly speaking) two tasks: first, 'Quantize' all the input signals. Second, 'Encode' this result. In other words, take the result of the Quantization phase and convert it to 1s and 0s to compress it.

Quantizer: Think of the Quantizer's job as smearing an image. The result is an image that's less sharp, more blurry but still has the same size. Mathematically, let's pretend the audio file inputs can take on values from 1-100 (RGB images take on values from 1-255 for example). Next, the Quantizer maps all inputs from 1-10 to the an output of 5. Then, it maps all inputs from 11-20 to 15. The result is much less detailed and smoothed out. This is where the error or quality loss occurs! Why do this then? It's all a trade off between quality loss and file size reduction. Quantization is lossy, but it's not compression!

Eg. inputs: 1 5 10 20 50 100

output: 5 5 5 15 45 95

We still have the same number of symbols, so we lost information but we did not compress the file!

Encoder: The 'Encoders' job is to perform lossless compression. It takes in input symbols and converts them to 1s and 0s. How does it do it? This is what Information Theory is really all about! In general, out of the input symbols, 5 5 5 15 45 95, 5 repeats the most. So, the encoder will assign it the symbol 0! In other words, assign the most frequently occurring symbols as few bits as possible! Putting it another way, the input symbols with the least information get assigned the fewest bits. There are many encoding methods out there (Huffman Encoding, Arithmetic Encoding). All work differently and produce different results but the bottom line is *encoding is a lossless compression* process.

Finally, you should be able to guess that .WAV files are much bigger and have higher quality because they are not quantized (or not significantly). Because of this, the quality does not suffer. Also, there are fewer repeating symbols at the input of the encoder and it is more difficult to encode/compress the file (highest compression is achieved when symbols repeat more often).

Using the MP3 codec however, the input files are quantized much more, and so a quality loss occurred. However, because the data is smeared, more input symbols repeat and the encoder is able to compress the data much more. Hope this helped!

Post 2

Thanks for explaining WAV files. Now then, why can't I open WAV files (in Windows Media Player 11) from a certain source although I can open them in Gold Wave (audio editor)? After opening them in Gold Wave (or Twisted Wave on my iMac), I can do a simple save, without changing the format, and they play just fine. Any ideas?

Post 1

Hey just wanted to say thank you for posting something so straight forward and in plain english. I'm 22 but even I have a hard time trying to understand a lot of this computer lingo and things like that. I'm a musician and I am trying to get more into the new equipment they have, but a lot of it i dont understand to its full capacity. Reading posts like this thou should help me greatly i think. Thanks again!

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