Digital Audio Compression

"What turns me on about the digital age, what excited me personally, is that you have closed the gap between dreaming and doing. You see, it used to be that if you wanted to make a record of a song, you needed a studio and a producer. Now, you need a laptop. "

-Bono

Digital Compression

Compression of different files is necessary for easy storage and transmission. However, it is important to understand what is being sacrificed for the sake of convenience.

To determine the impact of compression in audio files, I picked the song " Thunder" by Imagine Dragons, recorded in the Album Bravo Hits 2017. The original file format of the music above is .flac then compressed to different mp3 bit rates. The Conversion tool used for this activity is To MP3Converter Free downloaded from the Apple Store.

File Size

The audio file has been compressed in different bit rates: 32, 96, 128, 160, 192, 256, 320 kbps. Below is a table that shows the file size and the percent of decrease from the original file size.

With the continuous compression of the music file into smaller file sizes, there is an evident decline in the quality of the sound. In the original version, the interplay between sound sources is very clear and distinct from each one at the same time, each contributed to a harmonious blend. In the compressed files, especially at 32kbps, some instruments became indistinguishable and worse, it sounded like background noise.

Aside from the general clarity of the original version compared to the muffled music in the compressed versions, the notable difference is heard in the bass, drums and voice quality. In the original version, some sounds were intentionally more powerful to stress the essence of the song - Thunder signifying power and energy. The compressed version has reduced this and equalised the strength of each sound source.

Even in 65.41% decrease in the file size at 320kbps, the quality deterioration due to compression is still inaudible. It is until 128kbps with 85.97% decrease in file size that the difference in quality is distinguishable. However, with high quality headphones, this sound is still acceptable. It only becomes intolerable when at 96kbps and definitely a NO at 32kbps. Thus, the most efficient file size for storage and transmission at a still good quality level is 160 kbps.