Oh, the elusive phenomenon of ear fatigue. While not technically a clinical diagnosis, it's an ailment that nearly everyone has experienced after being subjected to adequate sound levels for enough time. As musicians, producers and audio engineers, it's important to understand more about the qualitative and quantitative aspects of ear fatigue (and how to avoid it) to better understand ourselves and our work.
What is ear fatigue, and how can we avoid it? Ear fatigue is a physical and psychoacoustic phenomenon where our sense of hearing worsens over time as we're exposed to sound pressure. As ear fatigue sets in, we lose our objectivity in fully understanding what we're hearing, leading to poor decision-making in music production tasks.
In this article, we'll go into more detail on what ear fatigue is, what causes it, and, most importantly, a variety of strategies to avoid it while we work on our craft.
Disclaimer: I am not a medical professional. I am an audio engineer. This article and website as a whole are for informational purposes only and should not be taken as professional medical advice. Please consult a medical professional in your jurisdiction for medical advice.
What Is Ear Fatigue?
First off, I should mention that ear fatigue is completely reversible and is much different than hearing damage.
Hearing damage/loss, whether to the sterocilia (the tiny hairs of the inner that vibrate when exposed to sound waves), the cochlea (the fluid-filled, spiral-shaped cavity found in the inner ear), the eardrum (the thin, circular layer of tissue that separates your outer ear from your middle ear), the auditory nerve, or any other part of our auditory system, can be either temporary or permanent. Ear fatigue is not necessarily damaging, though we can certainly cause hearing damage if we push too far (and too loud) past the natural fatigue that happens.
Reversing ear fatigue takes time, but it's as simple as resting our ears from excessive sound wave stimuli. Temporary hearing damage is often treated similarly, though professional medical attention may be required. Permanent hearing damage cannot be fixed, though there are medical apparatuses (hearing aids) that can help mitigate the effects of hearing damage.
Ear fatigue, as the name would suggest, is a natural decrease of our hearing sensitivity as we're exposed to sound (music or otherwise) over extended periods of time. It's actually not a clinical diagnosis, though it's certainly an occurrence we've all experienced throughout longer listening sessions.
Ear fatigue has both physical and psychoacoustic portions to consider.
In terms of the physical, things are not nearly as bad as hearing damage. However, the different biological parts that make up our auditory system will fatigue over time, which is a part of the overall “ear fatigue” ailment. For example, the sensitive sterocilia are often the first to fatigue over extended listening periods.
The brain is, of course, part of the auditory system, and it, too, can become fatigued. This psychoacoustic fatigue is largely a defensive mechanism. Too much stimulus from certain sounds, whether of a specific frequency band, a specific rhythmic pulse, or excessive loudness, will trigger a defensive response where our brain and central nervous system become less sensitive to those sounds. For example, as an evolutionary trait, our hearing response will adjust rather quickly to rainfall in order for our sense of hearing to be better equipped to pick up on other noises in the wild.
So ear fatigue is caused by excessive and/or extended sound pressure levels.
The highest frequencies within our universally-accepted hearing range (20 Hz to 20,000 Hz) are often the first to start sounding different as our ears fatigue. These shorter waveforms demand higher rates of vibration within our auditory system, and these sound vibrations are more difficult to recreate, especially over time (both on a micro and macro scale), by the human body (it's also a big part in why children can hear higher into the 20-20,000 Hz range than adults).
Furthermore, we're not overly sensitive to high-frequency content, to begin with, particularly at healthy listening levels. We can hear high-frequency sound waves more clearly at higher sound pressure levels, although this comes with the risk of hearing damage.
Predominant timbral properties also become ill-defined as our ears fatigue. For example, we may begin second-guessing guitar tone after several straight hours of mixing because the harmonic content of the guitar, in this example, has triggered a desensitization within our auditory response.
We need to also be wary of the important midrange frequencies, which we are the most sensitive to. Any ear fatigue will worsen our objectivity in this range, and we can quickly ruin a mix by relying on fatigued ears to make mixing decisions in the midrange (loosely from about 250 to 6,000 Hz).
When it comes to music production, and especially to mixing and mastering, the reduced clarity and objectivity that comes with ear fatigue will lead us to make worse decisions than if our ears and hearing response were fresh. It's important, then, to understand ear fatigue, why it happens, and what we can do to minimize it when we're working.
Let's now move on to strategies for avoiding ear fatigue.
Avoid Ear Fatigue By Developing A Strong Workflow
The best advice I have for you to avoid ear fatigue (other than monitoring at appropriate levels, which is next) is to develop an easy-to-follow and effective workflow.
Having a dedicated workflow to follow will allow you to make decisions more easily and save you more time in production, mixing, and mastering. Getting your work done in less time means that you will spend less time exposed to sound, which in turn, will reduce the ear fatigue you experience.
Speaking of workflow and mixing, my personal mixing workflow (that I use in each and every one of my mixes) is as follows:
- Prepare, organize and route the mix session
- Get the initial balance
- Process the tracks/subgroups and refine processing (bulk of the mixing)
- Add automation and extra production techniques
- Finalize the mix
Improve your workflow and more with my free guide (featured below):
I would even include time spent just before mixing part of the workflow in this case. To avoid ear fatigue, we can opt to focus on doing productive “quiet time” work before, after, and during the breaks in our mixing sessions. And while we should prime our ears by listening to a few professional reference mixes before we dive into our own mixing endeavours, we should avoid listening to loud sound sources inside and outside the studio on recording, producing, mixing and mastering days.
If you'd like to learn more about my workflow, check out the following video:
Avoid Ear Fatigue By Monitoring At Appropriate Levels
As I alluded to earlier, the easiest way to fatigue (and even damage) your ears is to listen to loud sound sources for extended periods of time. It makes perfect sense, then, that we may prolong the effects of ear fatigue by monitoring at more appropriate levels.
While critical listening should be done at various levels, 80 – 85 dB SPL seems to be the sweet spot with the best frequency balance and low risk of hearing damage.
You can check the dB SPL at your listening position fairly easily when monitoring on speakers with a dB meter (link to check a few great options out at Sweetwater). Measuring the exact sound pressure level when monitoring through headphones is more difficult, and I'd recommend staying on the safe side and monitoring lower than you may want to (remember that headphone drivers are positioned right next to your eardrums and, in many cases, couple to your eardrums).
In general, low levels help us identify elements too low in the mix, while high levels let us hear/feel the mix at a higher risk of hearing damage.
This is largely because of our non-linear sense of hearing. While the universally-accepted range of human hearing spans from 20 – 20,000 Hz, we're naturally more sensitive to midrange frequencies. The interesting part, however, is that our natural “frequency response” tends to flatten out at higher sound pressure levels, making the low and high frequencies more apparent.
So it's important to monitor at high levels for short periods, just as it's important to monitor at low levels some of the time, especially when mixing. But most importantly, we should avoid monitoring too loud (above the aforementioned 80 – 85 dB SPL) for extended periods of time in order to mitigate ear fatigue.
To learn more about decibels and appropriate listening levels, check out my article What Volume (In Decibels) Should Audio Be Mixed/Listened At?
Avoid Ear Fatigue By Avoiding Excess Clipping And Maintaining Dynamics In The Audio
Clipping can be a useful tool in mixing to add perceived loudness, distortion and special effects.
Compressing the dynamics of our audio is a much more common process, allowing us to shape the sound, control dynamic levels (the difference between the “loudest” and “quietest” parts of the signal), and glue elements together.
However, when overdone, this clipping can decrease the time it takes for ear fatigue to set in.
Consider how audio signals and sound waves mimic each other. When we compress and clip our audio signals, we effectively flatten the peaks. When it comes time to monitor such audio signals, our hearing system will react accordingly, with more time spent at the “extremes” of the maximum and minimum sound pressure levels.
While this is often subtle, the compression of audio signals causes a somewhat unnatural response in our auditory system, which can contribute to a hastening of ear fatigue.
In addition to the wave compression, the distortion inherent in these compressed/clipped waves produces additional harmonic content, which can also act to tire our ears more quickly.
Avoid Ear Fatigue By Taking Frequent Breaks
It's tempting, when we get into a flow state, to continue working on our mixes for extended periods of time. I've been there, mixing away into the early morning, only to have my mix sound worse than it did before midnight when I listened back the following day.
The truth is that ear fatigue will set in, and we will surely lose our objectivity as we spend more time in a mix.
The easiest solution to this problem is to schedule frequent breaks during your mixing endeavours.
I like the Pomodoro Technique, which splits work time into intervals with short breaks in between. I'll often mix for 30 minutes and then take a 5-minute break for multiple sessions in a row.
This allows me to focus intently for a shorter amount of time, which helps with productivity while also taking much-needed ear breaks in between. I'll often stretch, get some fresh air, grab a drink, meditate and/or do some “quiet time” work in between these mixing sessions.
If you'd like more productivity techniques for music production, check out my ebook 67 Productivity Hacks For Modern Music Producers.
Avoid Ear Fatigue By Restricting Working Hours
This strategy piggybacks on the previous one. When I write about restricting working hours, I mean knowing when to wrap things up for the day, especially when it comes to mixing.
We can employ all the techniques in this article to help prolong the “freshness” of our ears, but ear fatigue will set in throughout the day. Knowing when you've hit the point of diminishing returns can be difficult, but it's often best to stop mixing at some point within the day to reduce the effects of ear fatigue.
Note that I'm mostly concerned with mixing (and mastering) here. We can certainly switch to tasks that don't require as much critical listening to fill up our working time throughout the day. Things like editing, file management, client outreach, and more can be done with fatigued ears without much risk of worsening our mixes.
Avoid Ear Fatigue By Monitoring On Speakers More Than Headphones
In a previous strategy, I mentioned how much easier it is to measure the exact sound pressure level at your listening position when monitoring through speakers rather than headphones. This is one reason to consider monitoring primarily on studio monitors.
Studio monitors also interact with the environment, making them interact a bit more naturally with our ears.
Headphones have drivers immediately next to our ears (or even in our ear canal), which can lead to more ear fatigue due to proximity. In closed-back designs, the driver diaphragm will often be coupled (at least partially) to our eardrum, which can tire it out more quickly. Open-back headphones can help with this coupling, though they still have drivers right beside our ears.
For more information on monitoring on headphones and studio monitors, check out my article Mixing: Monitoring On Headphones Vs. Studio Monitors.
Avoid Ear Fatigue By Understanding The Signs
Our auditory system has the tendency to naturally adjust to what we're hearing. It's largely a safety mechanism, as was discussed in the section What Is Ear Fatigue?
So the longer we mix, the less objective we naturally become in our decision-making. Furthermore, we aren't particularly good at noticing the gradual fatiguing of our ears as it happens in real time. It's similar to the boiling frog apologue, where we often won't notice until it's too late.
So here are a few signs that you may be experiencing ear fatigue:
- General discomfort in the ears (this is also a sign of hearing damage).
- General fatigue: the brain uses a lot of energy processing sound, especially when we're listening critically.
- The seeming need to use more EQ than you normally would, especially with top-end boosts.
- An increase in frequency masking compared to previous listening sessions.
Sometimes a short break can refresh our ears in a way that can reduce or even eliminate the symptoms described above. Other times, we'll need longer breaks and some quality sleep in order to come back refreshed.
Avoid Ear Fatigue By Thinking Long-Term
One strategy to help avoid mixing and mastering with fatigued ears is to think long-term in your career.
You always want to put your best foot forward, so to speak, and while hitting deadlines is important, it's important to consider ear fatigue and its detrimental effects on your mixing decisions when procrastinating and trying to mix everything the night before the due date.
When possible, start early and take your time with mixing and mastering. Of course, don't spend too much time meandering in the mix, but don't rush it, either.
Even if it's only stopping “early”, taking a night to rest and double-checking your mix in the morning with refreshed ears, thinking ahead can help avoid the pitfalls of mixing with ear fatigue.
Is it better to mix on headphones or studio monitors? It's possible to mix professionally with only headphones or studio monitors, though better to use both to switch up our monitoring and improve translatability. Headphones are great for isolating the stereo channels and the acoustic environment, while studio monitors yield a more natural response.
What volume should audio be listened to and mixed at? Critical listening should be done at various levels, though 80 – 85 dB SPL is the sweet spot with the best frequency balance and low risk of hearing damage. Low levels help us identify elements too low in the mix, while high levels let us hear/feel the mix at a higher risk of hearing damage.