I remember the discussion in early 2022 between Mike and I in my bedroom in the mid-afternoon, toiling over how to get Disomus launched. We had had many conversations like that on an almost nightly basis even months before, but that day was different. I forget if I said it or he did, but somehow the idea of building an escape room on a flatbed trailer and bringing it to conventions and events sprung up. It was fascinating to see Mike’s mind race with the possibilities. We discussed the obstacles and agreed they’d be mostly solvable. We had Arduinos and Raspberry Pis on the mind, after a recent project with them. We looked up the prices of a trailer and it was shockingly achievable. So rare is it that a grand ambition is actually within reach. We ended the night with more discussion and excitement to take the year and build an elaborate fantasy game in a trailer that he could tow state to state, covering more ground than probably any other escape experience on Earth — then he booked a show for June and we built a sci-fi game instead.
My name is Davey Perron and I figured I’d take this opportunity to contribute to Disomus Academy and do a bit of a deep dive into the sound design on SALIENT and talk about the challenges we encountered in designing an immersive audio system for an interactive game like that. It was an absolute blast to work on and we learned so much. Mike and I both agree that there is a woefully small supply of educational resources for projects like this, and the bastard greybeards on Arduino forums seem to never comprehend the questions you ask and whether something like this is even achievable. Mike and I achieved it, so let’s pull back the curtain and look behind the scenes at the sounds and science behind SALIENT.
THE TECH
The majority of SALIENT runs off a central Arduino as well as satellite Arduinos for each puzzle. As such, we needed some kind of audio technology that could synergize with them well. Mike admittedly took the reins here and discovered two crucial pieces of technology for the game: WavTriggers and Adafruit Sound FX Boards, which are tiny soundboards you can pre-load .wavs/.oggs on and trigger via Arduino (or any voltage signal really). While a bit clunky to work with, these two hardware solution made integration of audio into the game very easy, once you learn the little idiosyncrasies of each.
The first audio system we discussed was installing a soundbar and subwoofer, impressed by the Sony soundbar we just installed in the living room. The architecture of the game would eventually reveal that to be impractical to implement, so we instead endeavored to have every puzzle have built-in speakers and have local soundsources for everything. It was quickly realized that small speakers in certain puzzles weren’t really up to snuff for the level of immersion we were aiming for. The vestiges of that system still exist in the Power Puzzle, which has two speakers built-in near the handles. It played this weird static electricity cracking sound that honestly didn’t sound great. Although we did implement this system, we ended up discarding it in favor of shifting the majority of the audio to the 4.1 speaker system installed in the walls. There are still local speakers installed in the Security Console and Tank Puzzle though and they work great for grabbing people’s attention at the moment we want. It was a good lesson that you should really aim for a hybrid system of local/global audio.
Mike did most of the research on the speaker systems, bouncing ideas off me for sanity checks. He had a bit more experience with installing livesound than I did, ironically (yet he still listened to my poor suggestions). We had an old, cheap surround sound system in our garage from when we used to work out in the garage, several hundred pounds ago. It wasn’t in use anymore so we tested it in my home studio/bedroom and sure enough it worked well! The thing could get incredibly loud so it was a seemingly perfect solution for our needs. We really wanted to capture this insane, gut-rumbling bass at times and have directional audio as much as we could for heightened immersion. However, we did find that the tweeters in some of the speakers weren’t really doing it for us, so Mike ordered standalone Pyle speakers that could be mounted.
We spliced them into the 4.1 signal paths and voila — audio implemented! There were trade-offs we made, such as realizing that we could only really do stereo, but spread across 4 speakers. This was due to the WavTrigger that was controlling the central audio only having support for two channels. It’s little compromises in tech that make building experiences like this very difficult when you’re on a tight budget, so we accepted our fate and pushed forward with just a two channel mix for now.
Mike and I often refer to what’s on the “Upgrade Path” of Salient, as we basically knew that we were going to be making concessions along the way to get the game finished in time for Living Dead Weekend 2022. A lot of the items on the Upgrade Path were shelved while the deadline neared, but on that list is to move to a true 4.1 or 5.1 surround sound system and integrate more audio feedback in certain areas.
THE SCORE
The score was an absolute blast to work on. It’s a rare opportunity for a composer to get to work on something that actually interests them and this was one of those opportunities. Mike and I share a mutual adoration for Day of the Dead and its unique synthesizer score by John Harrison. We wanted to bring that vibe to Salient, but in an underhanded way.
The main synth motif that plays throughout the game (at 30 second intervals by the way) was designed on a Behringer DeepMind12 layered with a Yamaha DX7 and Roland JX-8P. I really wanted to capture the sound of Prophet 5 rev.2, but my budget was a few orders of magnitude off, so I recreated the vibe with what I had.
Some of the ambient noise that plays in the background in the second half of the game was me passing some ambient audio through the WMDevices Geiger Counter. I initially had made that for fun months before Salient, but it was an eerie fit, so we used it to add some ambience to the game. The main “space” sound that plays when nothing is happening was a sample from a sound library that I mangled and looped.
Another inspiration for the score was Dying Light and it’s synth-inspired soundtrack. There is a quiet melody that plays in slow sections of the score that’s actually Mike trying his hand at a creepy melody on my JX-8P. I honestly loved the “sing-songy” feel of it so we threw it in behind everything.
The end track was thrown together quite literally at the last minute, as Mike wanted some outro music, like what would play during the end credits of a horror movie. I took the main synth motif, grabbed some LinnDrum samples, a DX7 for the bass, and got to work. I think it literally took like 15 to 30 minutes total and was thrown on just hours before he had to leave for the show, if I remember the timeline correctly.
THE DIALOGUE
The dialogue was a challenging project for reasons less to do with the technical side but more of the creative direction. Mike’s wife, Monica, is the woman over the intercom who directs you what to do. Being that it’s a Mike and Davey project, we crammed Day of the Dead references in there for some reason, such as “Jesus, Mary, and Joseph… you actually did it!” Those with a keen ear will also hear in the distant audio “a surgeon named Bub?” from two people walking around on the ship.
Initially, I had done the voice lines but Mike was insistent on a female voice and my bass-baritone didn’t make the cut, so I recorded the lines solely to capture the right cadence for Monica. She did an excellent job, especially getting micromanaged (or should I say Michael-Managed?) by two rabid perfectionists. We used an SM7B and I ran her audio through Ignite Emissary, a free guitar amp sim that is honestly perfect for imparting a radio type feel on audio.
The other dialogue is on the telephone hint system. We charted previous waters and I attempted the lines. I did an alright job, but we wanted someone with a more authoritative, less-distinct voice. Our brother, Bobby, agreed to do it but also noted that we could probably use an AI voice generator. That turned out to be an excellent suggestion, as with just a few tweaks, we had perfectly usable dialogue. If you’re worried we took a job away from voice actor, don’t worry — we paid the AI the same as the other voice actors on the project.
I’m going to slip the Alien sounds in here as a technicality, since it could be speaking in its own language. This was very fun, as I got a chance to just make weird growly sounds in a microphone, which I have a shocking amount of experience with (see: Ultra Nightmare). I took my gibberish and passed it through ring modulation, phasers, comb filters, all sorts of weird stuff to get a creature that felt like its vocal cords were extremely resonant and pulsatory.
For a little inside scoop on what’s on the Upgrade Path here, we plan on animating the Alien so that it moves as you play the game and maybe looks around. We may implement some weird movement sounds to cover up the mechanisms so that it seems less like a mechanical thing and more organic. We’ll see if that pans out, but I hold out hope.
THE SOUNDS
The last component to my role in the audio department was to populate the game with interesting noises that would feel right at home on Nostromo, the ship from Alien. Mike had sent me tons of 10 hour ambient loops of spaceship sounds, so we had a pretty good library to attempt to emulate. There is an irony here that at the time, I wasn’t super interested in sound design and sound effects, but at the time of writing this (a little under two years after the game first launched), I LOVE sound design. At the time, with my limited sound design skillset, I tried to emulate those little ratchety sounds and beeps and boops that fill the sonic landscape of Alien. I later learned a lot of those sounds came from Electric Typewriters (and I have one dammit!), but we ended up doing something complete different and novel:
We had ambient audio and ship sounds that play throughout the whole game. On projects like this, it can be difficult to generate ideas when you have just a blank canvas in front of you, so one guiding principle I always keep in mind is to keep checking your reference material and look for ways to integrate it. Some of the clacking and typewriter-y sounds you hear in the game were made by taking the text of the Day of the Dead script, passing it through a morse code generator, and using that to drive a synth clicky sound. We chopped it up into interesting bits and threw it around as part of the room’s soundscape. Neat, huh?
For those who haven’t played the game, the game starts when an asteroid from the Oort cloud hits your ship, causing cascading power failures while you have an alien specimen onboard that’s in critical condition. Sonically, these sort of things are a ton of fun since you get to go crazy with all the ideas and impacts and everything. However, we also had to be mindful of the time limit. Initially, the game was only 4 minutes long, so we had no time to spare for me to wax poetically (or sonically, I guess) with the most magnificent spaceship impact aural experience ever to grace listeners. Back in 2021, my friend and I went outside and smashed washing machines while I recorded the whole thing, so I had some excellent spaceship smashing sounds and that’s what you hear in the beginning of Salient (note: you can buy a pack of 60 sound effects for just $5 here). The power down sound was a mixture of a sample we grabbed and some bass-drop synth thing I had made. I also added some alarms and static electricity sounds (made from tearing paper with an SM57 nearby — thanks Joe Ford) to make the whole thing feel epic. The impact didn’t happen where you are, but rather on a distant part of the ship, so a lot of it was low passed to mimic the sound of a distant impact.
The telephone hint system was a fun little project, lasting only a night or two. I initially sampled a VCR (sample pack here, only $2) for the hang up and pick up sounds of the scientist on the other end, but the WavTrigger was so quiet through the small handheld phone speaker that I had to smash everything with several limiters. That turned it into a garbled mess, so I resorted to sampling an old telephone handset hanging up, as well as the dial tone so it felt accurate. If I’ve learned anything in sound design, it’s that grabbing the actual sound source of the thing you’re trying to mimic is probably a good starting place. It sounds stupid and simple and that I’m dumb for not knowing that, but you’d be surprised how the sound of a phone hanging up sounds like a creaky floor, or smashing a washing machine sounds like a bow and arrow.
One running theme through the production of Salient is the idea of limitations and how to deal with them. Coming from the music world, I don’t have to give much thought to translating my work into different mediums. I can make a two channel , 32 bit floating point, WAV with a 192khz sample rate and no one will bat an eye at the 100+ MB file size. But on an Adafruit Sound FX board, which supports 16-bit, 44.1khz, 2MB total file storage limit, you have to get creative in how you render your audio. A few tricks I pulled out to get audio file size small enough but still high quality was to render things as purely mono, 22khz, 16 bit. You begin chopping things down to manageable, single digit size as you compromise on each element of the channels, sample rate, and bit depth. I dread the day I have to cut down lower than any of those and my thoughts and prayers go out to the poor NES audio teams that suffered through those audio dark ages. The CGA-era folks were doomed from the start.
The Power Puzzle has this huge whoosh and power up sound that shakes the floor as the room roars to life. That was difficult to achieve, as I’m always weary about pushing too much bass, but we realized that if we treated the bass as a transient item, you could have it come in super loud at first, and then fade to nothing and the illusion of heavy bass still lingered. That’s a fun sonic trick you can pull when in a pinch. It’s also worth discussing that limitations are what breed creativity, as almost every step of the way with an experience like this, you’ll have to compromise to meet reality and physics at some point.
We knew we wanted the Security Console to have an audio cue when it booted up to let players know to LOOK OVER HERE PLEASE. We tried a few different “DRT DRT” sounds and eventually, Mikey did it with his mouth and I re-created it with Vital so it was truly synthetic. The Security Console was initially going to play that sound every time you got it wrong, but it quickly became annoying to players, so we had it play just the one time. It’s funny watching the camera when people play and seeing them all turn their heads, right on cue, when that thing barks at them.
On the Upgrade Path for the sound effects is that I really want to replace any audio I didn’t sample or make myself, just for the pride of it. Additionally, I want to get more retro technology sampled and integrated into the panels and around the different areas, but one thing at a time…
CONCLUSION
That’s basically it on the audio side! SALIENT was an immense amount of fun and it’s the highest praise when I can say that a project like Salient didn’t feel like work most of the time. There is always the drudgery of exporting files, oops wrong bit depth, re-export, ad nauseum, but to have the opportunity to work on a project as unique, interactive, and challenging as this is a true treat. I’m very excited that Salient is now available for everyone to play at the Salem NH Flea Market. We have a lot of great upgrades planned for the game, as well as a whole slew of exciting projects on the way. We hope to bring the highest level of immersion in the business and if Salient is our first step, I don’t envy those who’ll try to match us going forward.