MP3 vs. M4A - comparing sound quality and file size

In this post, I made a comparison of sound quality and memory size between MP3 and M4A (HE-AAC - High Efficiency Advanced Audio Coding) files.

For this, I used two different songs and I converted both in MP3 and M4A formats, both set to 48 Kbps bitrate and 48 kHz sampling rate.

Gotye - Easy Way Out

Time: 01'57"

MP3, 48 Kbps @ 48 kHz - File Size: 748 KB

M4A, 48 Kbps @ 48 kHz - File Size: 704 KB

Rick Astley - Never Gonna Give You Up

Time: 03'33"

MP3, 48 Kbps @ 48 kHz - File Size: 1,25 MB

M4A, 48 Kbps @ 48 kHz - File Size: 1,23 MB

I have conclude that two songs converted to M4A format have a better sound quality than MP3 format, even though both were with the same bitrate and sampling rate, and M4A file is a little smaller than MP3 file.