Audio waveforms

The oscillators described above work above the human hearing range. At the audio frequencies (AF), oscillators use RC or LC combinations to determine the frequency. If LC circuits are used, inductances should be rather large, and ferromagnetic cores are necessary.
All RF oscillators generate a sine wave output. A pure sine wave represents energy at one and one frequency. Audio oscillators, do not necessarily concentrate all their energy at the single frequency. A pure AF sine wave, especially if it is continuous and frequency constant, causes mind fatigue. Perhaps you have experienced it.

The several musical instruments in a band or orchestra all of them sound different from each other, even when they play same note. The reason for this is that each instrument has the unique waveform of its own. A clarinet sounds different than the trumpet, which in turn sounds different than a piano.

Assume that you were to use an oscilloscope to look at waveforms of musical instruments. This can be done by using a high-fidelity microphone, a low distortion amplifier, and scope. You would see that each instrument has its own signature. Each instrument’s unique sound qualities can be regenerated by using AF oscillators whose waveform outputs match with the instrument.