Two other important features of timbre are attack and decay. Attack refers to the beginning buildup of a note. This means how quickly the instrument expresses all of its frequencies and if there are any differences in the onset of harmonics. Decay refers to how long the fundamental frequency and harmonics remain at their peak loudness until they start to disappear. For example, a trumpet has a very fast attack, leading to the sharp sound we associate with trumpets. In electronic instruments, attack and decay can be altered to mimic the sounds of other instruments or to create timbres that are not possible using string or wind instruments.
In this illustration, you can manipulate attack and decay of a sound and see how it changes the sound quality (timbre).
To see the illustration in full screen, which is recommended, press the Full Screen button, which appears at the top of the page.
Below is a list of the ways that you can alter the illustration. The settings include the following:
Play: will play to tone with the current settings listed below.
Play Series: will play a series of tones that will systematically vary the attack and decay of the tone.
Attack: controls the proportion of the tone for the attack.
Decay: controls the proportion of the tone for the decay.
Frequency (Hz): change the frequency of the tone.
Duration (ms): the duration of the tone in milleseconds.
Pressing this button restores the settings to their default values.