This audio format is actually better than lossless

Opus is far superior to AAC (which is only a little better than mp3 in terms of size and/or quality for the same size).  Both AAC and mp3 are legacy codecs.

I recently went through the research exercise of comparing Opus, AAC and mp3.  If you're worried about file size, then Opus is far far better at lower bitrates.  64kbps stereo in Opus sounds just as good as 128kbps in mp3, AAC needs a little bit less bitrate than mp3 to sound the same.  The differences between all of them lessen as the bitrate goes up.

Of course, sounding the same is subjective to some degree, and the effectiveness of all lossy codecs is dependent on what is being encoded.  They all do better with less dense music, such as rock and roll; classical music, with the number of things going on really stretches them.  There, Opus again is the clear winner, particularly at lower bitrates.

The only real advantage of AAC AND mp3 is that they tend to be universally supported.  But that is changing as well.  Youtube, for example, has used Opus for several years.

I recognize that the article was mainly about lossless vs lossy codecs, but you can do much better than AAC today.

@artisan-radio I've always been with mp3s. I can usually tell the difference between mp3 and wav (often anyway), but since most of my library had usually been mp3 that's what I commonly stuck with - perhaps not ideal but to be honest I didn't really realize that mp3 use had fell by the wayside.. guess I'm behind the times. I worry about being sure a quality sound card is in the mix but perhaps that's a little counter-productive considering I've used mp3 now considered to he sub-par.

I use only MP3s as it is compatible with everything and my volume leveller app(MP3 Gain) only works with MP3s. As for the audio quality as I posted before the other ones mentioned(lossless) for us makes no difference in the end as for what we are listening to, and on, you don't know the difference. 256 kbps MP3 is more than good enough and 128 is fine. All you are doing is using up more space on storage for nothing. If you had a 25,000 Macintosh system for an example and you did a blind test not knowing what you were listening to and listened to the exact same piece of music with all of them and you were under 30 years old with excellent hearing and could actually hear to close to the 20khz they say you are supposed to you "may" hear a subtle difference between 256 MP3 and these other formats mentioned and the so called lossless ones. You are limited by the Realteck sound card in the computer, your processor and the transmitter and the final thing(radio) you are listening on.
And that is, for most of us, AM radio. And even FM it doesn't change it. For us it doesn't matter one bit about the audio format. The audio format of 128kbps MP3 is better than the fidelity of even FM broadcast radio.

Artisan said:

"I recently went through the research exercise of comparing Opus, AAC and mp3. If you're worried about file size, then Opus is far far better at lower bitrates. 64kbps stereo in Opus sounds just as good as 128kbps in mp3, AAC needs a little bit less bitrate than mp3 to sound the same. The differences between all of them lessen as the bitrate goes up."

MP3 128kbps and if it makes you happier 256kbps is more than good enough. There is nothing in music above 15klz anyways including symbols and a tamborine or a "triangle" instrument used in classical and jazz. The most you may hear with one audio format to another is definition in what you do hear in your hearing range and that would only be on the expensive hi fi system I mentioned. Not what we do. And surely not with AM radio.
Thinking that MP3 is outdated and another format is superior and you will hear a sound quality difference, is just to make you feel better that you have lossless audio and the mind can be fooled into thinking it sounds better because it's supposed to. 
You know, snake oil! like the $200 audio cables compared to the $20 ones. 

You only really have to worry about the codec if you're dealing with low bitrates.  And even then, the source material makes more of a difference.

For example, if you're doing 50s & 60s music, mostly mono from 45's, or vintage jazz, 64kbps mp3 mono is just fine.  96kbps is transparent.  For stereo, 160-192kbps is transparent for any type of music, and you'd be hard pressed to notice any difference at 128kbps.  Recording at 320kbps is way overkill.  You might as well just use FLAC.

For OTR, I don't notice much difference between between 32kbps mono and 64kbps mono mp3.  The better sounding files are from better recordings, not bitrates.  New recordings by the OTRR from transcription disk are usually at 128kbps, but again, that tends to be overkill.

I use OPUS for storage on my phone, as there is (relatively) limited storage compared to my desktop (which has 18+TB including external storage).  I store OTR (on the phone) at 16kbps and it sounds just fine.  Any type of music I store at 32kbps (original # of channels, vbr) and again, it sounds really good for the type of listening I do.  I'm sure it would sound a bit better at double those bitrates, but then, I'd only be able to store half the content, and right now, my storage is filled (at 1.5TB - I pretty much have my entire music library on my phone!).

Opus has some really nice features.  It tends to be smart (or, at least, the programmers were), falling back to mono if your bitrate is too low for the music content, and also with its vbr.

The one advantage mp3 has is that it is universally supported, but that is changing as streamers and music content providers recognize the size/quality advantage of Opus.