The goal of an audiophile is to achieve the high-fidelity sound reproduction that emulates live music performance. It's like going to live shows without actually going through sound.
Air: The impression of space and openness given by the headphones or IEMs
Ambiance: General mood or feeling evoked by the acoustics; the acoustic imagery you have when you go to a concert hall.
Analytical: The detail of the sounds; you can hear each instrument or sound individually. The opposite is getting a muffled sound where all sounds feel like a blotch of sound.
Bass: It is a lower frequency sound.
Bloom: It means music that can give the sense of space, fullness without compromise, and a sense of warmth. It's like being filled with the sound.
Brightness: It's boosting the upper and upper-midrange frequencies; hissing sounds are high frequency. It usually clarifies the instruments and the separation of each sound. However, too much can lead to the feeling of too "electric" sound.
Clarity/Crisp: It's the feeling of hearing every sound distinctively.
Depth: It describes the spacing of the instruments from back to front.
Midrange/Mids: Typically, the sounds of instruments and vocals.
Neutral: When someone says the neutral sound, the sound has not been affected by equalizers or device faults.
Openness: it's a feeling that the music is presented in an "open space" where the instruments are separated in their locations. You may have noticed that some songs give you the impression that the sound is behind or in front of you. Some other songs give you a clear picture of sounds moving from left to right.
Soundstage: It's the quality of how the music presents its sounds in an imaginary 3D space. People usually like that because it creates the closest sensation of being in live music performance.
Tremble: When you play cymbal sound, you get a lot of trembles. That's the high pitch notes and sounds. It also gives clarity, but too much of it sounds too noisy.
Warm: It is a quality to describe vocal sounds that envelop listeners' ears. Imagine listening to Whitney Houston's music. Her voice is warm.