https://www.musical-u.com/learn/how-do-i-train-my-ear-for-frequencies/
Ear training is not just for improvising and composing. If you are interested in recording and mixing your music, then you must train those ears to hear frequencies!
Learn how to get started with frequency ear training in this free article.
https://www.musical-u.com/learn/how-do-i-train-my-ear-for-frequencies/