Audio I/O and Waveform Generation

Record and play audio from devices, read and write audio files, generate waveforms

Audio Toolbox™ enables real-time audio input and output. Using the enhanced functionality of Audio Toolbox audio I/O, you can interact with the low-latency ASIO™ driver on Windows^®, selectively map to and from device channels, and control your device bit depth. To manage a database of audio files, use audioDatastore.

You can also generate tunable periodic waveforms to create test signals, control signals, and your own unique sounds.

Apps

Audio Viewer

View and play audio signals (Since R2024a)

Functions

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Audio File I/O

`audioDatastore`	Datastore for collection of audio files
`dsp.AudioFileWriter`	Stream to audio file
`dsp.AudioFileReader`	Stream from audio file
`audioEnvelope`	Compute envelope of an audio file (Since R2023a)

Audio Device I/O

`audioPlayerRecorder`	Simultaneously play and record using an audio device
`audioDeviceReader`	Record from sound card
`audioDeviceWriter`	Play to sound card
`asiosettings`	Open settings panel for ASIO driver
`getAudioDevices`	List available audio devices

Waveform Generation

`audioOscillator`	Generate sine, square, and sawtooth waveforms
`wavetableSynthesizer`	Generate periodic signal from single-cycle waveforms
`pinknoise`	Generate pink noise

Blocks

Audio Device Reader	Record from sound card
Audio Device Writer	Play to sound card
From Multimedia File	Stream from multimedia file
To Multimedia File	Stream video frames and audio samples to multimedia file
Wavetable Synthesizer	Generate periodic signal from single-cycle waveforms (Since R2020a)
Audio Oscillator	Generate sine, square, and sawtooth waveforms (Since R2020a)
Colored Noise	Generate colored noise signal

Topics

Real-Time Audio in MATLAB
Create a script to process and analyze real-time audio signals.
Audio I/O: Buffering, Latency, and Throughput
Learn key terminology and basic techniques for optimizing stream processing algorithms.
Plot Large Audio Files
Plot large audio files in MATLAB using the audio envelope.

Featured Examples

Create an App to Play and Visualize Audio Files

Create an app in App Designer to play and visualize audio files.

Open App

Measure Audio Latency

Measure the latency of an audio device. The example uses audioLatencyMeasurementExampleApp which in turn uses audioPlayerRecorder along with a test signal and cross correlation to determine latency. To avoid disk access interference, the test signal is loaded into a dsp.AsyncBuffer object first, and frames are streamed from that object through the audio device.

Open Script

Measure Performance of Streaming Real-Time Audio Algorithms

Presents a utility that can be used to analyze the timing performance of signal processing algorithms designed for real-time streaming applications.

Open Script

THD+N Measurement with Tone-Tracking

Measure total harmonic distortion and noise level of audio input and output devices.

Open Model

Measure Impulse Response of an Audio System

The impulse response (IR) is an important tool for characterizing or representing a linear time-invariant (LTI) system. The impulseResponseMeasurer enables you to measure and capture the impulse response of audio systems, including:

Open Live Script

Measure Frequency Response of an Audio Device

The frequency response (FR) is an important tool for characterizing the fidelity of an audio device or component.

Open Live Script

Simulation of a Plucked String

Simulate a plucked string using digital waveguide synthesis.

Open Model