This is known as auditory masking, this allows the discarding of data with minimal loss of quality.
7 Hold the 'Command' key and click the MP4 music files you want to convert to MP3 in order to highlight the. 4 Select the 'MP3 Encoder' from the 'Import Settings' menu. Select 'Add File to Library' or 'Add Folder to iTunes. 3 Open iTunes preferences, select the 'General' settings tab, and click the 'Import Settings' button. The human hearing system cannot hear quiet sounds in the presence of loud sounds of a similar frequency for example, a voice conversation cannot be heard while an aeroplane flies low overhead. If you dont see the menu bar, press Alt to make it appear. The current variant is specified in ISO/IEC standard 14496-3. It is also part of the MPEG-4 standard, it is most widely used to create small digital audio files. It too compresses digital audio files but to a bigger degree. Apple are the biggest users of this format and if you have an iPod or iPhone then you will have come across this format as it is iTunes default audio format.ĪAC is similar in concept to MP3 but goes further. It is at least one tenth the size of CD digital data. AAC is about half the size of MP3 but with better quality. It essentially cuts out, or compresses, information that the human ear cannot pick up thereby making digital files smaller and more easily managed and therefore quicker to download.
The difference is massive and so are the download times.ĪAC is similar to MP3. RAW file formats generally require 176,000 bytes per second compared to a lossy format which requires 17,600. By using lossy formats it enables even dial up users to download mp3 files at a reasonable speed. The reason lossy formats are used over RAW is that RAW audio files are too large to travel over the internet at any great speed.
In other words, that means it removes the information that your ear doesn't notice thereby making the file smaller. Instead, MP3 files use perceptual coding.
That means that an MP3 file does not contain 100% of the original audio information. This then enables you to get hundreds of songs on to a CD and it also has opened up a new market over the internet - the download market as download times have been significantly reduced. MP3 gets rid of a lot of the information recorded in a song that our ears are not able to hear and then uses complex algorithms to reduce the file size. MP3 is a digital music format which allows CD tracks to be reduced to around a tenth of their normal size without a significant loss of quality. It helps you convert and download youtube videos to mp3 or mp4 files for free.