How to: Ringing Orb sound

One sound you may want to create is a ringing sound - the sound of an orb that is resonating with pure energy.

The key to a ringing sound is to use a sine wave oscillator. A sine wave is the purest sound wave you can generate, and it is perfect for creating a sound that is clear and resonant. You would rarely hear a single frequency so perfectly in nature, and so it can create a sense of otherworldly energy.

Here is an example of how you could make the sound of a ringing orb using .esfx:

Play(duration=5s, cutoff=0.5s) {
	Oscillator(freq=800, harmonics=[1,1.5])
	LowPass(freq=200)
	Tremolo(volumeModulation=0.4) {
		Oscillator(freq=6.67)
	}
	Envelope(attack=0.5s)
}

The Oscillator function generates a sine wave at 800 Hz, which is a high frequency that will make the sound feel clear and resonant. We add some harmonics to the sound by setting the harmonics parameter to [1,1.5]. The 1.5 harmonic because that creates a perfect fifth, which is the most harmonic interval in music. This makes it sound like the orb is resonating with itself in a way that is pleasing to the ear.

The LowPass function filters out frequencies above 200 Hz, which keeps only the lower frequency hum of the orb.

We use the Tremolo function to make the orb sound like it is pulsing with energy. We use a slow pulsing frequency of 6.67 Hz (less than the minimum frequency of human hearing 20 Hz) so that you can hear the individual pulses of energy.

Finally, the Envelope function makes the sound ramp up to maximum volume over 0.5s so you can hear the orb slowly fade in. Because we haven't specified a sustain or release parameter, the sound will automatically release over the remaining duration of the sound effect, which gives our ringing orb a slow gentle fade out.