What is an MP3 or a WAV file

At the last computer session a couple questions were asked that got me looking for more specific answers about MP3 format for music than I had sought before. I found out more information than I knew before and I also found that there is a whole lot more that I could learn and I would consider the additional amount to be more than I need or want to know. However having said that I will still go ahead and write some of it here and hope that someone wants to know a bit more and I can present it in a way that is interesting. Much additional information is available on the Internet.

All data, including music is stored in a computer storage device or on a CD by a digital system. The data is all zeros or ones. The letter A is digitally 01000001. The asterisk symbol * is digitized as 00101010. With eight 0's and 1's which would be an 8 bit system 256 different symbols can be designated. Some computers use 16 bit, 32 bit, 64 bit and even 128 bit systems.

The next step upwards is the byte which is defined as 8 bits. 1024 bytes is 1 kilobyte. 1024 kilobytes equals 1 megabyte. 1024 megabytes equals 1 gigabytes. Just recently the terabyte has become common and it is 1024 gigabytes. Why does a kilo equal a thousand in the metric system but a kilobyte equals 1024? It simply is easier to say 1 kilobyte instead of being exact and saying 1.024 kilobyte. And why 1024 instead of 1000? Again it is simple. There are 2 numbers used in the binary digital system, a 0 and a 1, which has also been called yes and no, or open and shut. When the number 2 in multiplied to the power of ten it is 1024. Or another way to show it is 2x2x2x2x2x2x2x2x2x2= 1024

WAV (or WAVE), short for Waveform audio format, is a Microsoft and IBM audio file format standard. This is the format that most CDs use to store music. On a standard CD-R a laser shines a beam of light at the disc and reads the reflection of the beam. If the light is reflected to the sensor it is a one, if the light is not reflected to the sensor it is a zero. When the music is read from the CD there are 44,100 readings taken every second. Each reading is 2 bytes or 16 bits long. In a stereo system a reading is taken for each speaker. So each second of music on a CD requires 1,411,200 bits or 176,000 bytes. This is 44,100 samples/second x 16 bits/sample x 2 speakers/8 (bits per byte). Thus a three and half minute song requires almost 37 million bytes or 37 megabytes of space. This means that a standard CD could only hold about 18 songs. A few more songs can be put on if they are shorter in length.

MP3 is an abbreviation for Moving Picture Experts Group audio Layer-3. You can see why the name was shortened. It is a different format that is called a lossy format. It simply means that some of the information that is used on the lossless WAV format of a CD is lost when it is converted to the MP3 format. The loss is considered acceptable based on three characteristics of the human ear. 1. The human ear does not hear certain sounds. 2. Certain sounds are heard better than others. 3. Of two sounds the human ear hears the loudest but not the softer sound. Using these three facts parts of the music is eliminated without causing noticeable quality loss for most people. The rest of the music is compressed, shrinking the size of the file by a large amount. An MP3 files is about 1/10 the size of the lossless standard CD music. This allows music to be transmitted across the Internet in minutes instead of hours. Most burners recognize any format of music including MP3 and will burn them so that the average CD player can play them. More music cannot be burned to a CD and have an average CD player read the music. The computer hard drive or a thumb can hold nearly ten times more MP3 music than it can the regular CD music format. It will play on the computer or can be uploaded to a MP3 device.

There are many small files that will convert WAV files to MP3 files available for free on the Internet simply by searching for MP3 conversion. If you are like me the quality of a MP3 file is as good as I can hear and I don't miss the information that is lost when it is converted. However if your are an audiophile and your ears are extremely sensitive you may notice the lost information.