How and What:
1) Hearing live music. As an extension, being trained to play in an ensemble. Are either required? As @whart has written multiple times...no, but the skills can be applied to listening to a home audio system.
2) Listening to a familiar recording across multiple systems, sometimes with the guidance of the system’s owners to be made aware of elements/aspects in a system’s sound. I hate hearing the same recordings over and over, but the fact is the process is extremely helpful when learning to listen to a system, then later when evaluating changes to a system...or evaluating an unfamiliar system.
3) Related to above - listening to tracks on test LPs or CDs: Stereophile, XLO,etc. Why is this helpful in learning how to listen? Each recording on a test disc is provided because it offers an example (or examples) of a particular quality: human voice, piano, venue cues, image depth/width. Liner notes usually explain what to listen for in each. Very, very helpful in the process of learning how to listen.
4) Someone to guide (or teach) during a listening session, preferably in one’s own system so the sound characteristics are familiar. I had a manufacturer once come to my home to demonstrate a component. Toward the end of the demo, he swapped in some footers he liked to use. We also compared to footers I owned. He offered some observations that were quite helpful, and provided a lesson in listening.
1) Hearing live music. As an extension, being trained to play in an ensemble. Are either required? As @whart has written multiple times...no, but the skills can be applied to listening to a home audio system.
2) Listening to a familiar recording across multiple systems, sometimes with the guidance of the system’s owners to be made aware of elements/aspects in a system’s sound. I hate hearing the same recordings over and over, but the fact is the process is extremely helpful when learning to listen to a system, then later when evaluating changes to a system...or evaluating an unfamiliar system.
3) Related to above - listening to tracks on test LPs or CDs: Stereophile, XLO,etc. Why is this helpful in learning how to listen? Each recording on a test disc is provided because it offers an example (or examples) of a particular quality: human voice, piano, venue cues, image depth/width. Liner notes usually explain what to listen for in each. Very, very helpful in the process of learning how to listen.
4) Someone to guide (or teach) during a listening session, preferably in one’s own system so the sound characteristics are familiar. I had a manufacturer once come to my home to demonstrate a component. Toward the end of the demo, he swapped in some footers he liked to use. We also compared to footers I owned. He offered some observations that were quite helpful, and provided a lesson in listening.