Building a Reactive Sci-Fi Corridor in Unity & Wwise

This project, a Sci-Fi Corridor built in Unity 6000.3.12f1 and integrated with AudioKinetic Wwise 2025.1.7, is a deep dive into technical troubleshooting and workflow optimization. Here is how I went from a silent scene to a seamless, humming environment.

Read Part 01 here

In this post, we will be exploring some of the sound design and asset creation; hopefully giving you an insight into the creative process.

Going Back to the Plan

In order to keep things moving along swiftly, you have to stay organised. Another point reiterated from the first post, but a rather important one, clearly. A key contributor to keeping organised throughout this project is the Asset Spreadsheet.

This spreadsheet has gone through some slight changes since the last post that you may notice. Most strikingly, there are a number of assets showing “Complete” for the Design and Implementation Status. Some Event Name/Soundfile Name entries have changed slightly to more accurately match their purpose.

E.g., “SFX_Door_HydraulicMech” is now “SFX_DoorOpen”; “SFX_Console_Hum” is now “SFX_Intercom_Noise”.

“Env_Spark_Electronics” has been crossed-out for the time being. I have left it on the spreadsheet, as truthfully I am unsure if it really needs adding. The hum and hiss layers playing give enough of an atmosphere to the scene already, and I don’t wish to overdilute it with sound.

The table itself is also titled “KASDPR001” (Konjure-Audio-Sound-Design Practice 001).

In practice, the Asset Spreadsheet/Tracker, whatever you call it, should be updated accurately and consistently for any changes in status, new sounds to make, and cutting the ones where it has been decided they wont make the cut. Keep yourself, and any others also working on the project, in the loop at all times and you’ll (hopefully) never get lost.

The last post generated a bit of interest in the spreadsheet template, so I’ve decided to make it available to download via this link!

Capturing Sounds

Recently, I’ve been putting together a compact field recording kit comprising of a Zoom F3 recorder, RODE NTG2 Shotgun Mic, and a very basic and cheap pistol grip + NEEWER shock mount, and a Blue Mantis windjammer. The idea behind this kit is to go out into he real world and capture recordings of sounds to use as source material when designing new ones (as well as some nature audio preservation projects, but that’s for another time!)

Using this set-up, I captured a handful of sounds that I intended to use for the SFX_Door_Open and Amb_Corridor_Air assets:

Various fan sources (computer intake fans; dehumidifier; and a small USB desktop fan
Material Scrapes/Friction (using my backpack, cardboard box, and fabric on surfaces)
Drawers opening and closing

For all the recorded sounds, I typically aimed for roughly 1-minute recordings each.

A key downfall of the RODE NTG2 is its 18dBA of self-noise, which became apparent when I imported the sounds to my DAW and was particularly noticeable on the recordings of scrapes and the drawers, as there was moments of “silence” throughout the recording(s) where noise was audible. Whilst 18dBA isn’t a catastrophic amount of noise, it isn’t the professional standard of <14dBA that you’d definitely get from the likes of a RODE NTG5 or a Sennheiser MKH 8018, or even the tiny EM272 Clippy’s, and required a bit of processing in Reaper to remove some noise.

Fortunately, Reaper has a great stock effect called ReaFIR, which is an FFT-based Dynamics Processing effect, used for removing constant background noise (hiss, fans, hum) and acting as a precise EQ, gate, or compressor. The general approach to using ReaFIR to de-noise a recording is as follows:

Set “Mode” to “Subtract”; Points to “Precise”; and FFT Size to at least “8192”
Loop a “silent” section of your audio (approx. 3-5s) where noise is present
Check the “Automatically build noise profile” box
Play the audio and let it loop a few times; you’ll notice the analyser comes to life and the red line moves.
Stop the loop, and un-check the “Automatically build noise profile” box.
Play the loop again, it should be pretty much silent.
Disengage the loop and check the rest of the audio recording for any artefacts introduced by the subtraction of the noise profile.

Granted, it’s not the most surgical and precise approach to noise reduction/removal, and I am sure that iZotope RX is a much better tool that I should spend more time learning to use for such tasks; but for the purposes of this basic test project, ReaFIR cleaned the noise up sufficiently. I’m only learning the basics here really, so I’m not going to lose sleep over noise too much.

A lot of the noise is in the high frequencies, so for low / low-mid sounds, a bit of EQ might be the only extra thing you need to get the noise fixed following something like ReaFIR – ultimately it depends on what your source is, the equipment you’re using, the intent for the sound, and whether you want to spend a time meticulously processing stuff before you can even use it and further process elsewhere.

Inside the DAW

As we touched on the Amb_Ship_Hum_Lp layer in the previous post, we shall only be looking at the following in this post:

Amb_Ship_Corridor_Air_Lp
SFX_Door_Open
SFX_Intercom_Noise
Fs_Metal_Grate

I had no particular order in mind when deciding which sound to move onto next, which probably contradicts my point about being organised, but again… tiny project! The first thing I made after the Amb_Ship_Hum_Lp layer, was the SFX_Door_Open sound. In my mind, I had the Death Star blast doors from Star Wars – you know that sharp, crisp “pssssshhhhh–tt” sound as they open before revealing a squad of Stormtroopers and the looming shadow of Darth Vader? Yeah, those ones.

Admittedly, I need to work a bit more on my ability to listen to a reference sound and pick it apart to figure out its component layers, as what I ended up making was nothing like what I’d imagined.

Instead of a sleek, high-tech vacuum seal, my raw layers steered me toward something far more industrial, mechanical, and heavy.

1. SFX_Door_Open

The Objective: Create a multi-tiered mechanical sequence for a heavy corridor door sliding into its housing unit.
The Recipe: I utilized the recordings of friction/scrapes of my fingernails and hand along the bottom of my backpack, and some cardboard. The recordings of the backpack were processed with the Nvk_Autodoppler effect to make it rise in pitch, whilst the recordings of the cardboard had the low frequencies EQ’d out and run through multiple stages of saturation before a fully wet convolution reverb to completely change the tone from a low-end rumbly scrape, to a shimmery, almost woosh-like sound. A small snippet of a fan recording was also processed to become the short “whirr” of the mechanism. These were then layered above two samples of a heavy, rusty door opening, from a FreeToUseSounds sample library. All layers were ran through MC_Variation Generator and I picked the best sounding one out and rendered it down to 48k Mono WAV.
Key Takeaway: Realism often comes from processing mundane, organic sources rather than using clean synthesizer patches. A simple backpack scrape, when Doppler-shifted and saturated, creates a much more convincing industrial pneumatic release than a generic white noise generator.

2. Amb_Ship_Corridor_Air_Lp

The Objective: Establish a non-fatiguing, continuous background atmosphere representing the corridor’s internal ventilation and life support systems.
The Recipe: The foundation here was the 1-minute recordings of the small USB desktop fan, computer intake fans, and dehumidifier. In its raw form, the blade clatter was far too recognizable. I used a steep low-pass filter to roll off everything above 350Hz, removing the mechanical treble entirely and leaving behind a deep, hollow air resonance. A slight cut in the high-frequencies to reduce the noise of a strand of hair stuck in the blades was also applied, though I found this let to a subtle variation in texture to the sound after further FX processing. To keep the loop from sounding static over long playthroughs, I introduced instances of FilterFreak2 to a couple of layers which give the sound some movement, as if air is being pushed through pipes and discharged. I added some air can bursts at sporadic points throughout the loop to add further detail.
Key Takeaway: An ambient loop’s primary job is to provide environment context without eating up valuable frequency real estate. Carving out the mid-range and treble from raw fan recordings protects the space needed for critical gameplay cues like footsteps.

3. SFX_Intercom_Noise

The Objective: Design an active, slightly unstable electrical “bleep-bloop” sound for the wall-mounted intercom.
The Recipe: For this asset, I did not use any recordings, and instead used Kilohearts Phase Plant to completely synthesise the sound. It comprises of a triangle oscillator; with pitch (semi) modulated by a S&H set to 3/16 sync rate, playing a legato C3 note. Bitcrushing, limiting and EQ is applied within Phase Plant to taste. The sound is then further processed with EQ, FilterFreak2, OTT, and multiple stages of compression/limiting. The result is a glitchy electronic sound, that I can only describe as random bleep-bloops mixed with the static from your Gran’s old CRT TV. Just as intended!
Key Takeaway: When you need a highly specific, vintage-digital aesthetic, synthesis gives you absolute control over the texture. Tying a Sample & Hold module to oscillator pitch in Phase Plant creates a perfectly erratic, glitchy telemetry baseline that would take hours to chop up manually from recordings.

4. Fs_Metal_Grate

The Objective: Design footsteps for the player traversing metal flooring grid plates.
The Recipe: Another use of software to design the sound here; this time using the Edward Ultimate Suite instrument in Kontakt. Unfortunately, I lack the space to set up a foley pit/stage at the moment, so I wasn’t able to record my own footsteps for this, however the Edward Ultimate Suite is a really great tool that can achieve more than a satisfactory result. I set both samplers in the instrument to “Boots”, one with Grate as the surface, the other with Metal as the surface. I tweaked the tones of each sampler to emphasise the “clang” of the grate, with a touch of weight from the metal. Looking at the asset I used for the floor, it’s mostly metal grating, so this matches the scene. I wrote some MIDI notes to get about 8 steps in total and then rendered this to audio. As it rendered a loop, and I want individual steps (to use in a Random Container later in Wwise), I used Dynamic Split to split the loop wherever the gate opens and closes, and ended up with separated footstep items. To speed up rendering these, I used a script to create regions around selected items, apply a S-fade to the selected items, and then rendered via the Region Render Matrix as “Fs_Metal_Grate_001”, “[…]_002”, etc.
Key Takeaway: When physical space constraints prevent a custom foley session, high-end sampler instruments like Edward Ultimate Suite are completely viable alternatives. The real work shifts from the recording stage to the editing stage, using dynamic splitting and region matrices to rapidly batch-render randomized variations for the middleware container.

Thank you for reading and following me along my sound design journey! In the next post, I’ll dive into how I actually got these sounds from Reaper into Wwise, and thus, into the scene in Unity!

Until next time!

Sound Design Journey 002