Audio Editing: What are kbps, Hz and bit for Audio?Audio Tutorials Tutorials
October 4, 2014
Audio Editing: What are kbps, Hz and bit for Audio?
You probably use digital audio on a frequent basis, but you may not be completely clear about the way it works. Bitrate and sample rate were created to take sounds from the real world and represent them in a digital medium. Bitrate is the amount of information placed into an amount of time. A file’s sample rate is the frequency with which information is recorded in the file. Both of these affect the resolution, or quality, of the file.
Understanding Bitrate and Sample Rate
Digital media takes time as we perceive it and breaks it up into tiny measurements. These are like the ticking of a clock, and the rate of ticks is measured in hertz, or Hz.
The range of volumes that are describable is called the bitrate. When the bitrate is higher, the communication of volume is more accurate. Bitrate may be interpreted as the quality in the sound. Higher bitrates equal smoother sound.
Hz is a measurement for the characteristics of original audio pieces being fed to encoders. Hz also measures the decompressed audio output.
In audio, Hz designates the cycles per second, which is the oscillation frequency. When you listen to music, the sound that you hear as pitch is based on the frequency. The human range is generally thought to be between 20 Hz to 20k Hz, where 1 kHz equals 1000 Hz.
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8 Hz would be too low to allow for any easily discernible pitch. A range approaching 25k Hz is above the range that humans can hear, so unless you’re editing a dog whistle audio, you won’t need to go that high. The highest pitch reproduced by an FM radio is 15 kHz.
What Are Kbps?
Kbps refers to the codec’s bitrate, and in many cases MP3 codecs. It equals the number of bits processed or conveyed per unit of time. Varying codecs have various efficiency levels. For voice-only free editing, 24 kbps is a good, clean level.
When MP3 audio is compressed for online editing, the files created won’t sound exactly the same as the original. That is because it is a “lossy” format, meaning that some degradation may occur when making smaller files.
When you are editing audio from quality sources like Storyblocks, you can select how much information your MP3 file will lose or retain when it is encoded and compressed. You can even create different MP3s with different qualities of sound, and file size, from the original source. The key to this is the kbps, or bitrate, the number of bits per second that are encoded in the audio file.
If you are editing audio files, to experience the best music, you will find that MP3 files are considered inferior in quality to vinyl records and CDs. However, it is believed that the human ear cannot detect the difference consistently.