Keep pushing!

Don't worry too much about leveling up. Just focus on the training itself. Try your best with each question and if you get it wrong, take note of how the audio sounded and what the correct answer was. As you progress try to relate certain frequencies with noises you are familiar with. For example, around 4K to me sounds like someone saying Shhh, while 8K sounds like hissing. Overtime you'll get a sense of how each frequency band sounds but the only way you can get there is with consistent daily practice

Try other music.
For me this helped a lot.

Wow so many interesting approaches and opinions! Loved all the posts and strongly agree with each point.

Good luck & all the best with your training!

I found that trying consistently with pink noise helped train my ear better, and then I was able to hear the nuances on other instruments. One thing to remember is to be patient. This can be frustrating, but once you start hearing different frequencies, you will be impressed on how far you have come.

In addition to the suggestions mentioned, I found this helpful when somebody posted it a while back. It is a video that explains how different frequency bands can sound like vowels or hissing (like Oh, Ah, Eh, Ee, and hissing sounds). (This is the same as what Kevin mentions above.)

This describes how it works: .

There is a website where you can practice: https://webtet.net/apcl/#/parametric

I found that working on this a bit before doing Peak Master game helped and I tended to do it as a warmup to my SoundGym workout. The website allows you to use noise or to load a sound file. I would suggest using the noise to get used to the sounds you hear, then see how it works with audio (try a song you are familiar with).

Also in the Peak Master game itself, when I had trouble, I would hit the back button so that it would load the same song, I found that I struggled differently with different songs, so if I simply hit the Play Again button, it would load a different song and it was better for me to practice the same song in one session.