INFLUENCE OF THE BIT RATE ON THE SOUND QUALITY OF AN MP3 FILE
The term bit rate means how much information was transmitted per unit of time. Encoding in MP3 files can be done with constant and variable bitrate. Usually it determines the sound quality and consequently the file size.
In normal practice, the bit rate for high-quality recording starts at 128 kbps. Although this is a purely subjective opinion and for everyone it can have its own value. It is undeniable that the higher the bit rate, the better the sound quality.
At a value of 320 kbps, the sound of an MP3 file is already difficult to distinguish from the original by the human ear.
The following table shows the comparative characteristics of the sound quality of a certain bitrate value with equivalents that are understandable to everyone. Although, we repeat, this is a subjective opinion.
Bitrate value comparison:
Bitrate (kbps) —– Mono / Stereo Equivalent
8 mono —– Telephone conversation
16 mono —– shortwave radio
32 monkey
—– Medium Wave Radio 64 Stereo FM Radio
96 stereo —– Nearly CD quality
128 stereo —– CD quality
Now let’s try to do a little quality comparative analysis of MP3 files of a certain bit rate with originals:
• 112 kbps: the sound is unnatural, the sound is far from the original. Almost any listener will notice the difference. Encoding with these parameters is ideal for listening to melodies through mobile phones (although progress has come a long way and 112 kbps is no longer sufficient on some devices). It is also very attractive for broadcasting live broadcasts over long distances.
• 128 kbit / s: many manufacturers consider this value as the standard for encoding (this is highly debatable). The quality is more or less acceptable here. Many music lovers will note that the recording is not original. Although, thanks to the many “manufacturers” of CDs, users will soon accept this quality as a source. The records can be comfortably listened to on jarring plastic office speakers, cheap headphones and iPods, and of course cell phones. If you need to recode this recording to WAV format, you will lose your sense of taste forever.
• 160 kbps – here the situation is much better than before. Many will no longer understand the difference, and those who notice slight discrepancies with the original, put 192 kbps. This bit rate suits you 100%.
• 256 or 360 kbps: For many people it will be impossible to tell the difference in sound. Recommended for fans of high quality sound, owners of hi-fi equipment, large flash players, etc.
In the following table, we will consider the effect of bitrate size on the amount of disk space occupied and the number of files that can be placed on a certain amount of media. As a comparative value, we take a sound file with a duration of four minutes, which corresponds to the average composition.
This table does not include heavier discs like DVD or the latest standards like HD DVD and Blu-Ray. But even from the last column, you can imagine how much information, even with the best quality, can be put into the new media formats.
File and disk size dependency on bit rate
Bit rate (kbit / s) 4 minute files in 64MB RAM 4 minute files on CD (650MB) Hours on CD (650MB) 4 minute files on 1GB
64 34355 24543
80 28 284 19 437
96 22237 16364128
18177
12273160
14142 9218192 12118
8182256 8 89 6137
Perhaps the greatest amount of software has been written for the MP3 format.
Not a single self-respecting software player developer, and even home gamers, will dare today not to provide support for the famous format for their creation. He’s at the top of his form, experiencing a real boom. All computers likely contain files of this type, while others have thousands of them (downloaded from the Internet or copied from discs). People are buying turntables that have become outrageously cheaper. Stores are packed with MP3-tagged CDs. People already know this word as “CD” before.
However, despite all this apparent lack of clouds, the format also has disadvantages. This is imperfect stereo encoding, problems with gapped files, multi-channel sound, high frequencies and others. Many formats are already on their heels. This is the ubiquitous Microsoft with its WM A, OGG Vorbis and others.
But the most competitive now is probably the AAC format, which Apple actively and successfully supports and promotes on its iPods and the iTunes Internet service. There is also support from Dolby, Nokia (on new phones) and many other companies.
