Working with Audio

Updated: 13 Jan 2026

Overview #

Notch contains lots of tools that make it easy to design your looks to music, as well as ways t make your looks audio reactive. Audio can be played back or captured inside of Notch and then use in a wide range of audio reactive nodes inside the software.

Audio can also be captured from within a Notch Block and used to make audio reactive visuals in a live production environment. In multi-server setups it is also possible to analyse audio in a separate tool and send the resulting analysis data into your Notch Block.

Notch has the functionality to play back audio internally within Builder to allow users to build visuals to audio. However, in a live production environment it is not recommended to use Notch for the playback of audio. It is recommended to use a dedicated machine to handle audio playback, and receive an audio feed into Notch Blocks. See This Section for more information.

The Start of Noise: Sound Loader and Sound Capture #

These two nodes will get audio into your Notch project so that you can work to it and begin to dive into any audio reactive workflows.

The Sound Loader will let you load and playback an existing audio file. These are the accepted file formats for audio import into Notch:

• .mp3
• .ogg
• .wav
• .aif
• .aiff

As an audio file is imported into Notch, you might notice that a separate .fft file will be created in the same folder as the original audio. This file contains audio analysis data of your audio file, which to drive Notch’s audio reactive tools.

To get your audio to play, just connect the Sound Loader to the root node and hit play.

You can visualise the waveform of the audio on Notch’s timeline. The button with the waveform icon on the right side of the timeline lets you adjust the size of this waveform preview, choose if it is showing the left or right channel, and toggle the preview on or off.

There is a global audio mute button to the right of the waveform menu button.

Remember you can adjust a node in the timeline section to adjust where it is active on the timeline. This can be useful when working with multiple sound files on one timeline.

The Sound Capture node can be used to take a live audio source into Notch. This node will take an audio input from an Audio Device configured in the Project Settings (Project Menu → Audio Playback and Capture → Audio Capture Device).

Enabling “Pass Through Audio” on the Sound Capture node’s properties will allow you to listen to the audio that is being captured into Notch. Because the sound capture node is taking in audio in real time, it will not generate a waveform preview in the same way as the Sound Loader node does.

Timeline Markers #

Another useful feature when you’re working to audio with the Sound Loader node is Timeline Markers. These can be created anywhere on the timeline by moving your playhead to the part of the timeline where you want to create a marker and hitting Ctrl+M. This lets you quickly mark out sections of your music e.g. intro, verse, breakdown etc.

You can jump your playhead to the next timeline marker by holding Ctrl+Alt and pressing either the left or right arrow key.

You can also import timeline markers from a .csv file. To do this your .csv file can either be formatted as frame number:

#,Name,Start
M1,Candle,288
M2,Light,312
M3,In,383
M4,A,394
M5,Room,408

or timecode (HH::MM::SS::FF)

#,Name,Start
M1,Candle,00:00:04:48
M2,Light,00:00:05:12
M3,In,00:00:06:23
M4,A,00:00:06:34
M5,Room,00:00:06:48

Audio Reactive Nodes #

There is a good range of nodes that let you make any property or system inside of Notch audio reactive. There is detailed information on the inputs and properties of each of these nodes in the Nodes section of the manaul, but here’s an overview of each of the nodes and what they will let you do.

• Sound Modifier: This node will take incoming audio and use information about its frequency content and level to create a float value. That float value can be used in any numerical property within Notch, so this node is a really versatile way of translating audio into visuals. Because this node is working purely off of the level of the audio spectrum within a specified frequency range, it is really useful for making audio reactive content to long, evolving sounds or full stereo mixes. The response of the modifier can be tuned with the attack, decay and smoothing properties.
• Sound FFT Modifier and Sound FFT Region Modifier: This node is really handy for triggering changes in your visuals based on one specific sound within a mix, as it lets you pick out really precise parts of the incoming audio’s spectrum. By previewing the frequency vs amplitude graph of the incoming audio, you can look at exactly what part of that spectrum correlates with the audio element you want and then create a trigger when that sound is detected. This node is great for setting up audio reactive triggers based on percussive elements like kicks, snares, hi hats etc.
• Sound Effector: This node works similarly to a sound modifier, but plugs directly into Notch’s Cloner systems. Different nodes can be animated with different frequency bands within one node, so its a great way to get lots of audio reactive movement within a cloner system.
• Sound Texture: This node essentially creates a spectrogram of the incoming audio. Technically this is a video texture that represents the distribution of sound energy across the frequency spectrum. Creatively, this is an audio reactive input for anywhere that video textures are used. This could be used in many different ways, for example with displacement maps, Post-FX amount images, creating materials etc.
• Sound Deformer: This node lets you deform geometry based of the incoming audio signal. This can be a really great effect for introducing movement to the actual vertices of a mesh based on an audio signal. This node can also be tuned to specific frequency bands, and there is controls over its attack time, decay time and scale.

Common Properties of Audio Reactive Nodes #

Bands #

An audio source contains sound across the whole audible frequency spectrum. In order to tune the audio reactivity of the audio nodes, this incoming waveform is split into bands. If desired, you can choose one audio band that the node will react to. This can help make sure that the node is reacting to one specific element of an audio source.

Attack #

Attack determines the speed at which audio nodes will react to rising audio amplitude levels. A quicker attack time ensures a quicker reaction to quick, percussive transient sounds like drums.

Decay #

Decay determines the speed at which audio nodes will react to falling audio levels. A longer decay time ensures a longer tail off in response to quick, percussive transient sounds like drums.

Scale #

Scales the output value of the audio analysis.

Smoothness #

Applies a smoothing to the output of the audio analysis