*EDITORIAL* DX Listening Fatigue

Ever wondered why your head frequently aches after a solid workout on the mic?  Why, at the end of a rip-roaring DX marathon, your ears are throbbing like speakers at a heavy metal rock concert and you’re extra squirmy in the shack chair?

Well the cause is ‘Listener Fatigue’ and ask any Dx Adventure Radio Club (DA-RC) member who’s keyed up at a ‘Most Wanted’ DX entity before OR a dedicated DX Hunter who’s sat through hours of calling just to break through a pile up, and they’ll know EXACTLY what I’m talking about!

Ear-FatigueListener Fatigue (LF) is an authentic medical condition caused by adverse acoustic settings commonly affecting radio comms hobbyists.  Essentially, it’s so much more than your ears just getting tired.

In addition to headaches and restlessness, LF warning signs include agitation, drowsiness, discomfort, pain, a loss of sensitivity, tension and elevated blood pressure.  A very serious symptom too is that LF takes away enjoyment from our favourite hobby.

Causes of LF

First identified in the realm of Short Wave Listening (SWL) with military personnel during the World Wars but accepted in modern times as being prevalent in other fields such as music and construction, this much-maligned malady is defined by Wikipedia as…

“a phenomenon resulting from prolonged listening to sound whose distortion content is too low to be audible but high enough to be perceived subliminally, causing discomfort…”

The general consensus though is that LF isn’t just the result of subliminal listening of distorted audio.  Put simply, it’s caused by listening to audio that’s too loud and too muddy for far too long!

One of the most likely causes of LF amongst hams is what audiophiles call ‘sensory overload’.  This occurs when an op is exposed to a multitude of sounds from several different sources (e.g. a pileup).  It’s said that this overstimulation can result in general fatigue and loss of sensation in the ear which we now know are symptoms of LF.

Let’s explore these causes further…

In the world of radio comms, LF occurs when the ear tunes out unwanted noises such as QRN and QRM and focuses on the wanted ones (i.e. the incoming station’s TX). 

When listening to your transceiver, for example, the speakers may give off an unwanted hissing noise for long periods which you need to zone out on, thus causing LF.

As stated before, some LF stems from excessive exposure to unremitting TX audio, circumstances likely to be experienced during serious dxpedition work when the whole world wants to work you.  Here, the operator working the pileup must decipher signals through a wall of white noise, often under general physical fatigue caused by limited sleep too.  It’s not surprising this comes at a hefty physiological price!

Low signals, too, generally result in the volume being turned up which only adds to the vigor of the DX session and the propensity of an operator to succumb to LF.

For audio rack enthusiasts, the constant quest for greater loudness in TX audio, an obsession with pushing levels to the max + a lack of understanding of the complexity of amateur rig functions, can also lead to an increase in fatigue.  Remember — Incorrectly aligned studio rack equipment achieves the same acoustic fatigue for its listener as it does for its monitor.

Put simply, if you experience these above mentioned listening conditions for long periods of time then you will become fatigued.  Your ears will ache, your head will thump and the harsh symptoms of LF discussed earlier will invade your shack DX-istence.

How to Prevent LF

At first glance, it’d seem that reducing the noise and volume would be sufficient to reduce or prevent LF altogether.  Unfortunately, it’s not.

In cases of sensory overload not related to purposeful listening of hazardous noises, common ear protection such as earplugs and earmuffs can help alleviate the issue.  For hams, however, it’s not that simple.  We need the audio!

According to a new study conducted in Belgium (16 Division), spending just 1 hour listening to RX audio from your transceiver through headphones can damage your hearing.  Researchers at Ghent University studied 60 people and exposed them to audio through headphones at various volumes for 1 hour. 

Participants had their hearing tested before and after the experiment and researchers discovered that “significant threshold or emission shifts were observed between almost every session of the noise exposure group compared with the control group”.

This is what those findings means for us…

i) Take regular breaks

To protect your hearing, remember the 60/60 rule — listen to RX audio through your headphones for no more than 60 minutes at a time at 60% of maximum volume.  After prolonged exposure to loud listening levels, your ears’ ability to actually hear is reduced anyway so look at it like you’re doing your DXpedition team mates a favour by stepping out of the shack chair.  Basically, to reduce LF, share mic time and share the workload.

ii) Turn it down

What we as hams need to do is turn the damn volume down!  Even a notch or two can be enough to prolong one’s duty on the mic and reduce the onset of LF.


iii) Choose speakers wisely

The best speakers for listening longevity for musicians are said to be those with flat or gently rolled off treble response.  It’s hard to imagine that’s not the same case for hams.  Look at types such as PreSonus Eris E5, Focal Twin6 Be or ATC SCM25A Pro.

iv) Check speaker placement

Consider where you put any external speakers for your rig and experiment with placement.  A good way is to simply unplug or move one of the speakers and listen at a similar volume and chances are most of the “fatigue” you’ve been experiencing will disappear along with the harsh and aggressive sound from the mids and highs.

v) Use good headphones

Buy some good quality studio monitoring headphones with comfortable padding around the ears.  The best ones are Sony MDR7506, Sennheiser HD-280 Pro, Shure SRH840 and Beyerdynamic DT 880.

Remember the old adage too, “You get what you pay for…” so don’t skimp on price to save a few bucks.

When Will I Recover?

Depending on the level of sound and length of exposure, full recovery from listening fatigue can take anywhere from a few minutes away from the transceiver (short term fatigue) to several days (long term fatigue).

Rather than time, however, the most important thing is that the symptoms of LF have subsided and you’re feeling refreshed and ready to tackle the band again.

Hope this helps.

73 de Darren, 43DA001