ABSTRACT
This is called wavetable synthesis. For more realism, the attack or beginning portion of the recorded sound can be stored in addition to the periodic steady state part. Figure 2.1 shows the synthesis of a trumpet tone starting with an attack segment, followed by repetition of a periodic loop, ending with an enveloped decay (or release). “Envelope” is a synthesizer/computer music term for a time-varying gain change applied to a waveform or other parameter. Envelopes are often described by four components: the Attack Time; the Decay Time (“decay” here means the initial decay down to the steady state segment); the Sustain Level; and the Release Time (final decay). Hence, envelopes are sometimes called ADSRs.
