Ear fatigue is a common occurrence with people who work with noise. Exposure to excessive noise levels over time can lead to temporary and permanent hearing impairment or loss. Drinking ‘plenty of water’ and ‘turning down the volume’ is good advice, but it’s just the tip of the iceberg. There are ways to mix music for long periods without the risk of ear fatigue, and the same techniques will improve your final product.
What can I do to minimize the risks of ear fatigue? Spending too long at your workstation, working on a mix, and listening to tracks at high levels will unquestionably lead to ear fatigue. There are guidelines for noise exposure levels and times, which if followed, will reduce the risk of ear fatigue.
Your Working Environment and Workflow are more likely to minimize ear fatigue than drinking a glass of water!
Our ears are the most valuable resource we have in our home studios. We need to take good care of them and look out for signs of fatigue. Apart from the apparent health-related issues, ear fatigue can cause: wasted time and effort, poor musical decision-making, and can make us lose the inspiration for a particular song.
How can I recognize that I have ear fatigue? Below are some of the symptoms associated with ear fatigue:
Consult with a medical professional if you feel unwell.
A tired ear will behave differently to one that is fresh – here are a few of the things you may notice if you are experiencing ear fatigue:
Figure 1: Ear Fatigue Effects
Ear anatomy is generally split into three parts:
1. The Outer Ear: whose function is to funnel sound around us to the eardrum.
Sounds from around us are picked up by the outer ear as sound pressure waves. The waves are funneled and intensified by the outer ear, and cause the eardrum to vibrate. The eardrum is highly sensitive and reacts to pitch and amplitude changes in sound pressure.
2. The Middle Ear: which contains the eardrum. The eardrum is very sensitive and vibrates.
There is a fluid chamber on the inner side of the eardrum, and as the eardrum membrane vibrates, it causes the fluid to move inside the chamber. Contained in the fluid chamber are arrays of tiny, highly-sensitive hairs that sway in sympathy with the fluid.
3. The Inner Ear: which contains the auditory nerves - the processing part of the ear.
For each frequency band, low, low-mid, high-mid, and high, the hairs are different thicknesses and heights. For example, the hairs for sensing low frequency are short and thick, and the hairs for detecting high frequencies are long and thin. So depending on the fluid waves’ properties, the hair will sway or vibrate accordingly.
At the base of each hair, a tiny muscle picks up on the hair’s movement and converts the motion to an electrical impulse, which is sent via the auditory nerve to the brain’s cortex for decoding.
Figure 2: Ear Anatomy
When the eardrum membrane muscle and hair muscles are overworked and tired, their ability to work as they should is limited. For example, the eardrum cannot move the fluid effectively and moves more slowly. The flow will be slower, having less intensity.
On top of that, the hair muscles will not be able to function exactly how they should, so the unclear signal from the eardrum is muddied even more before being delivered to the auditory nerve.
Ear fatigue will occur if you allow yourself to be exposed to sound pressure levels that are too high.
The amount of risk for ear fatigue is summarized in Figure 3.
Figure 3: Risk of Ear Fatigue
If you listen to music for a short time, at a low volume, the risk is relatively small. If you listen to music for a long time, at a high volume, the risk is significantly higher. In past years, noise levels in the workplace have caught the attention of organizations, like OHSA (USA), NIOSH (USA), and HSE (UK/EU), and studies and guidelines have been drawn up.
|Guideline||8 Hours||Ex.Rate||4 Hours||Max|
|HSE 1989 (UK/EU)||85dBA||3dB||88dBA|
|HSE 2005 (UK/EU)||80dBA||3dB||83dBA||87dBA|
Table 1: Noise Level in the Workplace Guideline Comparison
The guidelines identify the SPLs of Time-weighted Averages (TWA) and recommend maximum exposure times. For example, OSHA recommends working no more than 8 hours in an environment with a 90dBA TWA. The guidelines also provide ‘exchange rates’ for increased SPL. Each increase in ‘exchange rate’ halves the recommended exposure time.
|SPL (TWA)||Max Exposure|
Table 2: Maximum Exposure Effect of Increased SPL : HSE 2005 (UK/EU)
Note 1: The guidelines provide little information on safe recovery times.
Note 2: Guidelines require workplaces to assess workers risks 5 decibels under the stated SPL level.
Note 3: HSE reduced their exposure SPL in 2005 by 5 decibels.
Regardless of which guidelines you consider to be correct, there is no real necessity to mix at 95dBA or 88dBA for four hours in a home studio.
When I calibrated my monitors to the K-20 system using pink noise, the level in my room was set at 79.3dBA.
(See the article about Pink Noise here.)
We saw in Figure 3 that risk is reduced when volume levels are low, or mixing time is shortened. In your own home studio if you want to work for 8 hours, your SPL (TWA) exposure, to meet the NIOSH guidleine, would be 85dBA.
This is still too high (especailly if you look at HSE 2005). By way of comparison, in my own studio my monitors are calibrated to K-20 and K-12, at 79.3dBA, which is lower than any of the recommended SPLs, but loud enough in my own environment to be able to hear details of kick drums, vocals, and high frequencies of a guitar.
Set your working SPL according to your monitors and room. Don’t use the arbitrary 86dBA.
The HSE 2005 guideline recommends that being exposed to 83dBA should be limited to 4 hours. But remember, that is a time-weighted average. That is the equivalent of consistently hearing 83dBA for 4 hours. So ... if your mute button is on for 2 out of 4 hours, that is already half the exposure (TWA will be lower), and therefore, you can work within the guideline for 8 hours.
If your monitors are calibrated to 86dBA (exchange rate of 3dB), the above scenario changes, and therefore, you could only work within the guidelines for 4 hours. But ... if your mute button is off for 30% of the time, you could work within the guidelines for 12 hours at 86dBA.
To me, this makes a lot of sense and logically directs risk reduction to three areas:
Don't let ear fatigue get in the way of your creative process. Consider a holistic approach to your health when mixing: stay hydrated, keep a good posture, and take regular breaks. Think about the ergonomics of your workstation. For example, monitoring height and seat height can help with good posture.
If you do plan to mix for 8 hours, avoid playing your mix constantly while you work. Short bursts of audio are preferred with a lot of thinking in between.
If you are like me, you also play in a band. Rehearsal, performance, teaching, practicing, and recording also needs attention for noise levels. For example, if you're playing at a gig, the SP level at your drum kit will peak at about 144dBA!
The build up of direct and reflected sounds in a practice room and in small stage gig areas can lead to excessive noise levels.
As a home studio owner, you need to manage your own sound levels and understand the risk not only in your studio but in other parts of your life too.
Finally ... If you're recording at home, try to keep levels down and try to get your musicians to play accurately and quietly.
Are there any frequencies that affect ear fatigue more than others? Ear fatigue is caused by the loudness of sounds more than particular wavelengths of frequency bands. However, some people complain that frequencies of 2kHz and above are worse than others. Don't over compress your mixes or put too much limiting on the 2 bus - a little is okay but leave volume maximizing for the mastering stage. Some tracks may have some unwanted frequencies recorded onto them so do a frequencies sweep and filter them out in the early stages.
How long does it take to recover from ear fatigue? Many mix engineers swear by a good night's sleep to null the effects of ear fatigue. However, recovery times are dependent on how much over the recommended SPL level you went, and how long you mixed for. Recovery time is also related to age and health - if you are young and healthy, you will probably recover in much less time than somebody older. Remember that ear fatigue can lead to impaired or permanent hearing loss, so don't exceed the guidelines and make sure your monitors are calibrated correctly.
Why are my ears ringing after mixing? The ringing in your ears is probably tinnitus. Either permanent or temporary damage has been done to your inner ear due to subjecting your ears to excessive amounts of sound pressure over a long time. See a doctor as soon as possible. if the ringing is temporary, it will fade away in time, but if it is permanent, there is little that can be done.
Back in 2009, I bought myself a copy of Pro Tools and recorded some home made music. It was challenging to start with, as I had no idea what I was doing. I made many mistakes on my journey - some fun, some expensive, and many time-consuming! I find running a Home Music Studio a fascinating and rewarding hobby and still enjoy it every day. This website is where I’d like to share everything that I’ve learned.