- Additive Synthesis, in which complex tones can be created by a stack of sine oscillators running at whole number multiples (harmonics) of a fundamental frequency.
- Only useful for explaining theory. Running a sufficient number of oscillators for most audio applications would be too computationally expense. Approaches such as subtractive and FM synthesis are much more efficient.
- Demonstrates how to load small audio samples and associate them with user interface events.
- Adds a popping aluminum can sound to a button's mousedown and mouseup events.
- Also provides alternative code (commented out) that demonstrates the use of an audio sprite.
- Demonstrates how to modulate the initial volume and harmonics of a note to simulate the attack and decay dynamics of a real musical instrument.
- Shows how to schedule events on the AudioContext timeline.
- FM Synthesis, which generates complex tones via frequency modulation, quickly varying the frequency of one oscillator with another.
- Also Vibrato, a slow oscillation in frequency that adds richness to a tone.
- Shows how the output from one AudioNode can be fed into an AudioParam of another AudioNode, causing its value to vary over time.
- Emulates a male singing a set of vowel sounds.
- Demonstrates how a set of bandpass filters can model the human vocal tract.
- Vowel formants are defined as parallel arrays of frequencies, Q-values (which define the width of bandpass) and amplitudes.
- A slider smoothly transitions from one vowel to the next.
- A simple hearing test. Generates a sine wave with a frequency that can be set between 20 Hz and 20,000 Hz, the range of human hearing.
- Demonstrates that humans perceive frequency logarithmically.
- The same audio processing chain as envelope.html except with a musical keyboard rendered in HTML instead of a frequency slider.
- A note can be sustained by dragging off the key before the mouseup event. Click on that key to cancel the note.
- Shows how to convert a MIDI note number to an oscillator frequency.
- Loads various audio loops and demonstrates the effect of high pass and low pass filters.
- Can switch the visualization between frequency bars and a spectrogram.
- Visualizes the input from the microphone as frequency bars or a spectrogram.
- Generates various types of noise:
- White - Equal power across all frequencies.
- Pink - Power decreases as frequency increases, favoring lower frequencies. This noise sounds more balanced and natural to human hearing.
- Brown - Favors lower frequencies even more strongly than pink noise.
- Demonstrates the use of ScriptProcessorNode.
- Subtractive Synthesis, in which the output from an oscillator with high frequency harmonic content (square, triangle and sawtooth waves) is modified using filters to create complex tones.