What users hear when using their virtual reality (VR) headsets is more than an afterthought. It influences perception, spatial awareness, and emotion. Developers can use it to sway their actions, guide them, or make the experience believable — that is, if they follow the principles of effective audio design.

The Importance of Effective Audio Design in VR

Poor audio design ruins immersion. The VR experience generally encompasses three general factors — visuals, touch, and audio. In other words, sound accounts for roughly 33% of immersion. Whether the application is video game development or virtual real estate showings, what users hear will be consequential.

The history of digital audio has laid the foundation for the sophisticated soundscapes accessible in VR today. The origins of digital audio date back to the early 1900s; and by the 1990s, digital audio workstations became commonplace, revolutionizing how sound was produced and manipulated. From there, advancements in immersive auditory experiences have been able to take off.

Today, many VR and augmented reality (AR) platforms offer drag-and-drop tools, allowing even those with little development experience to craft convincing soundscapes. In other words, users have come over the years to expect their products to have high-quality audio.

Beyond user expectations, sound also plays a central role in building spatial awareness. While relatively little is known about how individuals develop spatial presence in VR, their sense of direction, orientation, and distance effectively disappear in a virtual, three-dimensional (3D) environment. They need cues to orient themselves.

Professionals can even use sound to provoke intense emotions or desirable behavioral reactions, guiding a user to connect with a product on a profoundly personal level or compelling them to complete specific actions. Thus, VR developers should consider the impact of effective sound design on their final product.

Use Cases for Immersive Audio Experiences

Gaming is the leading application for VR. In fact, 72% of the people who have adopted this technology use it for immersive gameplay. As many gamers attest, sound design is equally vital to visual design. Video games must convince the player of the authenticity of the experience for hours on end, and audio is a significant factor in believability.

Social experiences like the Metaverse closely follow this concept. For users to feel like they are genuinely engaging with others, the virtual environment must feel real alongside low-poly props and cartoonish avatars.

The use cases for entertainment in virtual acoustic landscapes are interesting. With mixed reality (XR), developers can blend 3D visuals with spatial audio techniques, making concerts, orchestras and comedy shows incredibly immersive, even in venues not built for high-quality acoustics.

Achieving realism is critical in applications like virtual tourism, where people come for an experience indistinguishable from its in-person counterpart. Art exhibits, museums, and real estate showings would feel inexplicably uncanny without proper soundscapes.

In VR-powered education and training, a realistic simulation can be the difference between a passing or failing grade. For example, if a truck driver missed the auditory cues indicating the engine was overheating, their virtual 18-wheeler would break down, prompting an automatic fail.

While AR, VR and XR applications in health care are still in their infancy, studies have already linked their presence to better patient outcomes. Audio design has advanced therapeutic treatments for psychological and physiological conditions by enhancing the virtual environment’s emotional and cognitive impact.

The Principles of Audio Design in VR Development

VR developers should follow these principles of audio design.

1. Align Soundscapes With the Environment

You must replicate the noises objects and surfaces make in the real world. What does a user hear when they throw a rubber ball at a brick wall? Does it sound any different when it hits the player model? Will you have multiple instances of the same sound effect? To create convincing soundscapes, you must consider interplay, or how interactions change the acoustics.

2. Avoid Unnatural-Sounding Pure Tones

Pure tones are sounds with sinusoidal waveforms — sine waves of constant frequency and amplitude. They rarely occur in the real world, making their inclusion in a virtual one jarring and offputting. They are also challenging to spatialize with head-related transfer functions (HRTFs), so they are not worth the trouble.

3. Use Individualized HRTFs

HRTFs are commonly used for VR audio generation because they recreate natural sounds realistically. However, they vary from person to person.

The solution is individualization. Research shows this method can improve the subjective listening experience’s accuracy by around 33% by eliminating hearing location bias.

4. Place Audio Sources Within the Environment

Hearing two-dimensional “head-locked” loops takes users out of the experience. Spatialization responds to head tracking, enhancing immersion. Ensure you place cues accurately within the space.

5. Simulate Interaural Time Difference

The interaural time difference is the variation between sounds reaching each ear. It is crucial for localizing low-frequency sounds.

Users rely on it to determine the direction and distance of objects — specifically sources with frequencies below 1,500 Hertz — within virtual spaces. Effectiveness drops off at higher frequencies, resulting in intensity differences between ears.

Audio Design Should Be More Than an Afterthought

What will users hear when they slide their VR headset on and open your application? Whether your priority is captivating menu music or realistic in-game audio, you have the knowledge and tools to create a believable, enjoyable virtual acoustic landscape.

Eleanor Hecks is Editor-in-Chief of Designerly Magazine where she specializes in design, development and UX topics. Follow Designerly on X @Designerlymag.

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