Sine waves in sound design

A sine wave creates the most basic sound possible in electronic music. Sound designers talk about “pure” tones, meaning sine waves. Other types of waves are made up of multiple sine waves combined together.

What makes sine waves special

Pure sine waves contain only one frequency at a time. This means they make only one pitch without any extra tones. Most other sounds in nature and music contain many frequencies at once. Even when a flute plays a single note, the sound includes extra frequencies that make it sound like a flute.

How sine waves sound

Sine waves sound very smooth and round, without harshness or buzziness. Some say they sound hollow or empty because they lack the extra frequencies that most sounds have. When played at low frequencies, sine waves create very clean bass tones.

Creating sine waves

Sound designers create sine waves using oscillators. They can control three main things:

Frequency

The frequency controls how high or low the sine wave sounds. Higher frequencies make higher pitches. Lower frequencies make lower pitches. Humans can hear sine waves from about 20 Hz (very low) to 20,000 Hz (very high).

Amplitude

Amplitude means how loud the sine wave is. Sound designers can make sine waves louder or quieter by changing the amplitude. They often change the amplitude to make sounds fade in or out.

Phase

Phase describes where in its cycle the sine wave begins. While phase changes do not affect how a single sine wave sounds alone, phase becomes important when combining multiple sine waves together.

Uses in sound design

Bass Sounds

Sound designers often use sine waves to make bass sounds. Sine waves work well for bass because they create clear, strong, low frequencies without extra tones that might muddy the sound.

Testing

Many sound engineers use sine waves to test speakers and audio equipment. Because sine waves are so simple, they make spot problems with sound systems easy.

Sound Effects

Sine waves help create many electronic sound effects. By changing a sine wave’s frequency over time, sound designers can make sounds like sirens, computer beeps, and science fiction effects.

Musical Synthesis

Sound designers combine sine waves to create more complex sounds. This process, called additive synthesis, can create many different types of sounds. By combining the right sine waves, every musical sound can be created.

Working with sine waves

Sound designers often start with sine waves when creating new sounds. They might:

Layer them

Adding several sine waves at different frequencies creates richer sounds. This can make electronic versions of real instruments.

Change them over time

Changing the frequency of a sine wave while it plays creates interesting effects. Small changes make vibrato. Big changes make sweep effects.

Process them

Running sine waves through audio effects can create new sounds. Adding distortion makes them more complex, and adding echo makes them sound bigger.