What sensory overload is
“The thing about sensory overload is that it is the inability of the brain to filter out anything, because all things are information. Touch, sound, words, visual stimuli, light, dark, touch, even the body’s own systems such as heartbeat which is always in the background, the brain’s own electrical sound which is often received as perpetual tinnitus which most autisics/aspies listen through in order to hear their environment.”
“…it’s so loud, it’s deafening. Do not think in terms of volume as in loudness, but rather as in volume as in capacity ie. Too much information.”
“…multiple sounds from multiple objects/environment, immediate environment. All sound is at the same ‘volume’ as in level. So all sounds, regardless of level are received at the same ‘volume’ ie. there is no distinction between soft, light, quiet, loud, ear-shattering, ear-piercing…”
“Even though it is 7am and everyone else in the house is asleep, I can hear at equal volume:
- 8KHz fuzz from my brain
- The fan of my PC which modulates slightly
- My neck making small clicking noises as I move my head
- Some cars outside, even though the nearest road is about 100m away
- An aeroplane flying overhead, it is quite high and has propellers
- An external hard disk which has just “woken up” and the disk is spinning up
- A cat scratching in another room.”
The effect it has
“…if I can give you a visual example (as Autistic I think visually) I would say this: a photocopy of a photocopy of a photocopy, and then on and on and on until the original image is so degraded it cannot be understood … then [I experience the] blue screen of death type experience. This is the only way I can convey what it is like.”
“…remember analogue loop machine recorders where one would sample a sound and then loop it, and then be able to sample that and loop again?…”
“Sound becomes like finger nails going down a chalk board, which increase in intensity until it becomes one solid noise.”
“…distortion … a single phrase/voice saying something becomes repeated over and over again until it becomes so distorted it is unrecognisable and message is unable to be understood.”
“…think in terms of what a machine would do, or what would happen if a machine were overloaded, ie, a fuse blows, it heats up/overheats, things become distorted, computer gives blue screen of death…”
“Every vibration from them moving around in the flat above me, is as if someone is hovering directly over my head getting closer & closer. Until it literally feels as if they are walking all over my head. Yet others who are in my flat at the time & don’t have heightened senses usually claim they can’t even hear any noise.”
“When I’m at my computer & get sensory overload it can be like a glowing light is coming out of the computer. It quickly increases until it’s as if it’s going directly into my brain. That light beam becomes all that I can think about or see.”
‘Proximity Effect’ (autistic version…)
“A sound right in one’s face really isn’t very nice, it’s … like a needle under the skin, or a hostile attack.”
What abrupt noises do
“… [an] example: at a cafe, a waiter dropped a plate onto another plate behind the serving area. The sound was high piercing and sharp and physically experienced for me like a gun or a canon going off, it went right through my body, my whole being felt the sharpness of it. It made me jump. It jarred. It’s not nice. It feels hostile.”
What your own body sounds like if you experience sensory overload
“…the perpetual tinnitus, this sound is like the old TV’s when you unplug the aerial, but at a higher frequency. For me this frequency is about 8KHz.”
How it affects the day-to-day life of someone who experiences it
Perhaps the best example I can give you is if you have a bad hangover. You now have to go and do an IQ test whilst sitting in a children’s nursery full of playing / screaming kids. After 8 hours would you rather go home and sit quietly or go out to a party?
These are direct quotations from adults on the autistic spectrum. They gave their time generously and patiently to help me understand as best I can what overload feels like. This really helped me get inside little Hikaru’s head and I am very grateful to them.
Although, as one contributor pointed out, no one experience is the same, there is enough obvious common ground for us to agree comfortably that we can understand one another when we use the term ‘sensory overload’.
From these discussions, I isolated a series of aural-neurological phenomena:
- a build-up of simultaneous sonic events, for someone who cannot filter aural information as a typically-wired brain can, will easily tip the brain into distress and it shuts down into panic mode: the ‘blue screen of death’. There is no ‘cocktail party effect‘.
- Many people with autism cannot filter out their own body sounds, so they hear their brains as a kind of tinnitus, as well as other sounds from inside the body. A neurotypical person would only notice these things if in a place of unusual quiet.
- Sounds close up feel like invasions – proximity is amplified.
- Abrupt, sharp sounds are distressing and felt physically.
- When overload is triggered, it can be hard for the brain to stop processing sound information, and it sounds something like it would if I could put a delay plug-in on real life!
- Every day life with less neural filtering and different sensory information processing can be as exhausting as spending a working day in a room full of screaming children with a hangover while concentrating very hard on a difficult task. If an adult, who is accustomed to this experience of the world finds it this jarring and draining, imagine how a pre-school child, who has neither the learning nor the brain maturity to find coping mechanisms, would handle it!
So here is how I replicated it:
- The build up of events was generated by layering. I used the same recording of ‘party hubbub’ five times over, one in each channel clean, and then three processed with various distortions (chorus; phaser; enhanced reverbs). Each sound had a different EQ setting, automated to boost different frequencies at different times like a kind of sonic Mexican wave. I also automated the panning to add to the confusion. The distorted versions come in after the clean versions.
- I underlined this confusing version of ambience with sine wave drones on C0 and C1 to try and replicate the physical feeling of being invaded by the sound.
- The ‘tinnitus hum’ was easy, as someone had very helpfully given a description and even a frequency! I simply used Cubase’s built in synth, Retrologue, to add white noise and distortion to a C7 (roughly equivalent to 8KHz), playing by ear until it sounded like a high-pitched version of a de-tuned television hiss. This enters, you notice, as soon as we enter Hikaru’s point of audition and acts as a signpost. Although he is holding it together in the first picture of him in the temple, we are still starting to hear what he hears and the music is perhaps foreshadowing the meltdown to come.
- The abrupt and close-up sounds I chose to use were a loud man’s laugh and a chair being knocked down. Both of these sounds were heavily compressed and artificially raised in levels with make-up gain. They also both had some brutal EQ settings! The man’s voice was heavily boosted in a shallow curve peaking at 1000Hz, which is where his most penetrating overtones seemed to sit.
- Using a delay-plug in on these sounds to replicate the inability to finish processing a sound when the brain is tipping into overload didn’t seem to work as well as layering these sounds manually, so that is what I did. The chair had its lower frequencies enhanced in the repetitions of the sound, as though the brain is ‘dwelling’ on the boomy, thunderous quality within that sound.
- The chanting that we see pictured was also a good cue to bring in a sonic event hard to process, that might seem frightening to a little boy nearly at the point of sensory meltdown. I found a recording of Buddhist chanting and, again, I suppressed higher and enhanced lower frequencies as well as slightly time-stretching, to give a kind of submerged feeling to them. I felt this made the sound more threatening, as though muffled by a panicking brain. I also gave it its own special convolusion reverb.
- The chanting was layered with a special adulterated cello section, boosted at around 100Hz, treated with a distortion plug-in and put through an algorithm reverb and quite viciously panned, automated between extreme left and right . This was an attempt to pull out from the original sound something like what Hikaru might pick up from it after a moment, a sort of amplified, engorged, mechanised insect buzzing.
- The final sonic event is some tinging bells, which appear in the illustrations and I have also heard on recordings of chanting. I found a suitable bell sound, a brittle, high pitched instrument, then used a distorted piccolo to pick up the note and continue it, bending the pitch up and crescendoing towards the end of each one, like a piercing neural echo of the original, cutting, sound.
- This final event repeats with increasing rapidity, culminating in the climax that is Hikaru’s eventual meltdown. I emphasised this rising panic with a reversed cymbal and reversed triangles joining the piccolo.
During the meltdown itself, the tinnitus hiss and the low-frequency drones continue, as they represent internal sound and unrest, but the other events cut in and out, simultaneously and randomly, as though Hikaru’s brain is now processing the distressing onslaught of sound information in fits and starts, like a car engine spluttering and cutting in and out, perhaps. The music here features Hikaru’s inwardly resolving tritone motif: rapid, panicked, and played on a distorted piano sound.
I synced distorted, reversed taps on the mic with Hikaru banging his head to try and relieve the electrical storm inside it. These, the low-frequency drone and the tinnitus hiss continue into the garden, as the brain activity calms down. When the hiss cuts out, we know we are back to Sachiko’s point of audience.
Here is the entire sequence:
I think I learned more about sensory overload by doing this exercise than any of the reading I’ve done around the subject. My helpful autistic allies, by the way, confirmed that this section of sound is an accurate representation of what they experience in sensory overload.