How do you make audio visualization?

Audio visualization refers to translating audio signals into a visual representation. It involves using computer software to analyze sound frequencies and amplitudes, then render them as graphics that change and morph in sync with the music or sounds. People create audio visualizations for a variety of reasons:

To create visually engaging music videos, live performances, and other audio-reactive visual content.
As an analytical tool to study characteristics of sound and music.

As an accessibility aid for the hearing impaired.
For creative self-expression and experimentation with synesthetic art.

Audio visualization has many applications across media, music, accessibility, analytics, and art. Visualizing audio brings sound to life in innovative ways that captivate audiences.

Choosing Audio to Visualize

When selecting audio to visualize, you’ll want to consider factors like genre, tempo, and frequency range. The characteristics of the audio will greatly impact the look and feel of the visualization.

For example, faster tempos and more complex genres like electronic dance music tend to produce visualizations with more activity, color variety, and intricate patterns. Slower, mellower genres like ambient or classical music often result in smoother, more flowing visualizations.

The frequency content and dynamic range of the audio is also important. Songs with a wide stereo field and strong presence of low, mid, and high frequencies will generally visualize better than narrow, quiet recordings. Boosting frequencies with an EQ can help create a more vivid visualization if needed.

Testing different audio tracks is the best way to get a sense of how genre, tempo, and frequency balance affect the visual display. Choosing music that resonates both sonically and visually will make for the most compelling audio visualizations.

Overall, electronic and pop music with bright tonal balance and high energy tend to produce the most vivid results. But every audio clip offers unique visualization possibilities when paired with the right software and settings.

Visualization Software Options

There are many software options available for creating audio visualizations. Some popular professional tools include:

Adobe After Effects is a motion graphics and compositing software that allows users to create stunning audio reactive animations and visuals. Its robust toolset provides fine control over keyframing and effects to sync animations precisely to the audio waveform. After Effects is commonly used for music videos, concerts, and other video projects requiring dynamic visuals.

Blender is a free and open source 3D modeling and animation program. It can be used to create mesmerizing 3D visualizations that react to audio through its Python API. Blender allows full control over lighting, materials, animation, and rendering to produce high quality visuals. It has a steeper learning curve but very active community support.

TouchDesigner is a visual programming platform focused on real-time projects and interactive media. It is commonly used for live events and performances requiring audio reactive visuals in response to music. TouchDesigner connects both 2D and 3D animation tools with advanced audio analysis to build customized systems for visualization.

Overall, programs like After Effects, Blender, and TouchDesigner provide robust toolsets to create professional, production-ready audio visualizations. They give fine-grained control over animation and effects timed precisely to audio sources. Their workflows suit building complex reactive systems for music videos, live performances, and other creative projects.[1]

Waveform Visualization

Waveform visualization involves mapping the waveform of an audio track to visual elements. The audio waveform is a representation of the sound wave, with the amplitude shown on the y-axis and time along the x-axis. Peaks and valleys in the waveform correspond to louder and softer volumes.

To create a waveform visualization, the audio file is analyzed to generate waveform data. Software can then map the amplitude values to properties of visual elements. For example, the height or vertical position of objects could correspond to amplitude. Bars, lines, or other shapes would move up and down in time with the music. The width or colors of elements could also reflect waveform amplitude.

Advanced mappings might involve breaking the audio into multiple frequency ranges, and visualizing each range separately. The waveform could also be analyzed for transients like drum hits to trigger visual events. Overall, creatively mapping waveform amplitude and timing to visuals results in visualization that pulses and dances along with the music.

Frequency Spectrum Visualization

Frequency spectrum visualization maps the different frequencies contained in an audio clip to visual elements like color, shape, and movement. The audio is first processed through a Fourier Transform to convert the sound wave into frequency bands. The amplitude of each frequency band can then be extracted and mapped to properties of visuals elements.

For example, lower frequencies like bass could be mapped to darker blues and larger, slower moving shapes. Mid-range frequencies may be brighter greens and yellows with shapes that pulse to the beat. High frequencies like crisp high hats can be small, fast moving pink or red elements. The overall energy of the audio at a given moment can also drive effects like scaling the entire visual up and down with the volume.

By encoding so much musical information into visual variables, frequency spectrum visualization can create engaging real-time animations that bring the audio to life. The viewer gains deeper insight into the frequency composition of a piece of music. While fairly abstract, spectrum visualizations can take on an almost synesthetic quality with enough refinement in mapping sound energy to visual aesthetics. As discussed in Li et al. (2023), frequency spectrum analysis remains a core technique for generating audio reactive visuals and cross-modal representations.

Real-Time vs Pre-Rendered

There are two main approaches for creating audio visualizations: real-time rendering and pre-rendered animation. Real-time rendering generates the visualization in real time as the audio plays. This allows for a seamless, interactive experience where the visuals are smoothly synced and reactive to the audio frequencies and waveform. Pre-rendered animation involves creating the visualization ahead of time by rendering out each frame individually. The benefits of pre-rendering include:

Higher visual quality – With pre-rendering, each frame can be carefully crafted and rendered with more detail since you aren’t limited by real-time processing constraints.

Complexity – Pre-rendered animations can have extremely complex visuals, motion graphics, particles, etc. that may be difficult or impossible to calculate in real time.
Consistency – The final visualization will be consistent every time it’s played back since it’s not dependent on real-time calculations.

However, real-time audio visualization has the key benefits of interactivity and responsiveness. Since the visuals are generated instantly based on the live audio input, the experience is seamless and organic. Some advantages of real-time rendering include:

Synced visuals – The visualization stays perfectly in sync with the audio, even if the audio tempo changes.
Responsive – Visuals instantly respond to audio characteristics like frequency, amplitude, etc. This creates a tight audio/visual relationship.
Interactive – Real-time systems can incorporate interactive parameters that the user can control during playback to manipulate the visuals.

The choice between pre-rendered and real-time visualization depends on the specific goals and context. Pre-rendering prioritizes visual polish and complexity while real-time systems enable responsiveness and interactivity. Many projects combine both techniques, using pre-rendered elements with real-time audio analysis and effects.

Synesthesia in Audio Visualization

Synesthesia is a neurological phenomenon where stimulation of one sensory pathway leads to involuntary experiences in other sensory pathways. For example, synesthetes may see colors when they hear sounds or music. This cross-wiring of the senses can be harnessed in audio visualization to map sounds to visuals that evoke similar senses.

Auditory-visual synesthesia is one of the most common forms, where sounds trigger visualizations of colors, shapes, textures or movement. Skilled audio visual artists can create visuals that align with the synesthetic experiences of their audience. For example, high-pitched sounds may be visualized as bright flashes of light, while deep bass notes map to pulsating organic shapes. The timbre and tone of instrumentation can also be represented through specific colors, patterns and animations.

By tapping into synesthetic perceptions, audio reactive visuals can become more intuitive, emotional and absorbing. The visuals act as a bridge between sound and image, with the goal of enhancing the overall experience. Rather than random pretty shapes, the visuals are directly informed by the qualities of the audio being visualized. This creates a deeper audiovisual harmony.

Overall, leveraging cross-sensory associations through synesthesia allows visual artists to make more meaningful connections between sound and image. This results in visuals that closely align to the “feel” of the music.

Audio Reactive Visuals

Audio reactive visuals are visual elements that respond and change based on the audio input. Making visuals react to audio involves analyzing the audio signals and controlling visual parameters based on that analysis. Some key aspects of creating audio reactive visuals include:

Audio Analysis – The first step is analyzing characteristics of the audio, like amplitude, frequency, rhythm etc. Common analysis methods include FFT to analyze frequency spectrum, beat detection for rhythmic analysis, and envelope followers to analyze amplitude over time.

Parameter Mapping – The next step is mapping the audio analysis to parameters that control the visuals. For example, tying low frequency to scale of shapes, mid frequencies to rotations, and high frequencies to color. The mapping defines how the visuals will respond to the audio.

Choosing Visuals – The visual elements themselves can be anything – simple shapes, 3D models, particles, liquids, generative art etc. Choosing engaging visuals that respond well to audio creates an immersive audio reactive experience.

Real-time Rendering – Audio reactive visuals need to be rendered in real-time in sync with the audio. This requires efficient coding, optimization and leveraging GPU processing. Frame rate and latency need to be considered.

Some commonly used tools for audio reactive visuals include TouchDesigner, Unity, Blender, Processing, MAX/MSP and VVVV. With the right audio analysis, parameter mapping, visual design and real-time rendering, you can create beautiful immersive audio reactive visual experiences.

For a detailed tutorial on building live audio reactive visuals in TouchDesigner, check out this excellent resource – https://medium.com/@colinpatrickreid/building-a-live-custom-audio-reactive-visualization-in-touchdesigner-c195b7f591a7

Common Visualization Methods

There are several common techniques used to visualize audio:

Oscilloscope visualizations show the waveform of the audio signal, similar to an oscilloscope display. This provides a visual representation of the amplitude and frequency of the audio over time (Source).

Line animations use the audio levels to animate properties of lines like length, color, or movement. As the audio changes, the lines react accordingly. This creates a dynamic visual that pulses with the music (Source).

Particle effects utilize many small objects like dots, bars, or shapes that move and react based on characteristics of the audio. For example, the particles may pulse to the beat or flow in the direction of panned audio (Source).

These techniques provide visually engaging ways to represent audio that go beyond static waveforms. Animated visuals based on audio can create an immersive experience for the viewer.

Tips for Impactful Visuals

Here are some best practices for creating engaging, beautiful audio visualizations:

Choose colors carefully – Colors can evoke different emotions and reactions, so pick a palette that matches the mood of the music. Vibrant, saturated colors tend to pop more. Using too many discordant colors can make visuals messy.

Incorporate movement – Kinetic, flowing shapes and patterns that react to the music make visuals more dynamic and interesting to watch. Things like pulsing to the beat, growing/shrinking, and rotating can bring energy.

Sync animations to music – Visuals should respond and transform according to the tempo, rhythms, frequencies, volume, and vocals of the track. Well-synced animations create an immersive, multisensory experience.

Build slowly and pay off – Use intros, buildups, and drops in the music to guide the evolution of the visuals. Save large transformations and “pay off” moments for key sections to maximize impact.

Use 3D space – Layering visual elements at different depths creates a sense of perspective. This adds dimensionality and visual interest compared to flat 2D designs.

Incorporate variety – Having different components like shapes, textures, and effects that enter, transform, and exit keeps visuals novel and dynamic from start to finish.

Focus on highlighting music – The visuals should complement and accentuate the music experience, not distract from it. Draw attention to interesting musical qualities.

Match brand style – If creating visuals for a musician or brand, incorporate visual elements that align with their aesthetic for a cohesive look.

Consider purpose – Tailor the visuals to the intended use, whether for a music video, live show, background ambience, etc. Optimize visual intensity and complexity accordingly.