octave
12.22 octave. The interval between two tones whose frequencies (or fundamental frequencies) stand in the ratio of 2:1. Annotation 1 In the musical scale, notes that are an octave apart are given the same name, and the octave in which a tone occurs is designated by subscripts. Annotation 2 See Table 3.
interval
12.21 interval. Spacing in pitch or frequency, as indicated by context, between two tones. The frequency spacing is expressed by the ratio of the frequencies or by a specified logarithm of this ratio. Annotation See Table 2.
decay time
12.20 decay time. The amount of time taken for the amplitude of a sound to fall from one specified value to another. Annotation The tem is generally used to refer to the final portion of a sound.
rise time
12.19 rise time. The amount of time taken for the amplitude of a sound to rise from one specified value to another. Annotation The term is generally used to refer to the initial portion of a sound.
decay
12.18 decay. Term used to designate the final portion of a sound.