Four Phases of Tone: Attack, Sustain, Bloom, Decay

A Listening Experiment

Play middle C at medium volume, no pedals. Listen until the sound completely decays, usually 20 plus seconds. Repeat that same note, listening from attack through decay for an entire 10 minutes. This allows time to focus on aspects of tone of which you are not ordinarily conscious.
As your ears settle in, you may hear these four phases:

attack – the initial percussive sound
sustain – the sound of the struck pitch, middle C
bloom – a swell in tone volume
decay – a gradual dissipation of sound

Focus on attack and sustain.

Find words that describe what you heard.

Attack:   

Was the initial percussive sound…

crisp, short, clear, focused, a “cut edge”;
or
a clang, long, explosive, metallic, chaotic, painful?

Sustain:   

Did you hear the actual pitch middle C sing throughout much of the 20-second decay? Was the pitch middle C clearly present? Was it…

singing, straight, warm, spherical;

or, did the bottom fall out of the pitch, leaving a higher pitched sound for the rest of the decay? Was it…

choked, short, weak, top heavy, tubby, loud but unfocused, jangling?