Brian Cooley says consumer electronics are built with humans in mind, but our pets can see and hear much more than we do, meaning we could be bombarding them problematic sound and light.
By Brian Cooley*
Few of us would put up with a TV that emits an annoying whine or a light bulb that flickers, but for our pets, that may be the world around them.
Their senses are tuned differently than our own and may detect a confusion of noise and strobe effects that we don’t, particularly as we fill our homes with technology.
You can fix a beeping smoke detector quickly by changing the battery, but it might also be emitting a constant high-pitched noise that only your dog can perceive.
Have we built them an unintended hell?
Dr Sheila Carrera-Justiz, assistant professor of neurology at the University of Florida College of Veterinary Medicine, says that our pets’ sense of hearing makes the world a far different place for them than for you and me.
They hear everything we do, plus much more.
Ultrasound: The unheard screech
Dr Katherine Houpt, an environmental factors expert at Cornell University’s College of Veterinary Medicine, says pets routinely respond to sound above the frequencies humans can hear, called ultrasound.
“Many dogs are afraid of smoke alarms,” she says.
“So the dog is going crazy and the owner doesn’t know why.”
Humans nominally hear sound that ranges in frequency from the lowest bass around 20 Hz, or cycles per second, up to the highest, tingling treble near 20,000 Hz.
In reality, adults may only hear half of that range, as age reduces our sensitivity to high pitches.
But dogs can hear sounds up to 45,000 Hz and cats up to 64,000 Hz.
To them what we call “ultrasound” is just sound, but our gadgets aren’t designed with that in mind.
Consumer electronics eliminate only the high-pitched noise that we hear.
Our pets can be left with an unconsidered residual.
Silencing those sounds
What happens next isn’t so clear.
While we know that animals hear a vast amount of sound we’re deaf to, we don’t have as clear a handle on how it may affect them.
One possibility comes from Dr Jeremy G. Turner of the Southern Illinois University School of Medicine.
In a 2005 study on the effects of noise on lab animals, he noted that noise can alter the heart, sleep and endocrine cycles in animals and make them more susceptible to seizure.
A 2015 survey by a consortium of veterinary groups in the UK linked seizures in some cats with a phenomenon called feline audiogenic reflex seizures caused typically by high-frequency sounds.
The study named over a dozen ordinary household noises that appear to be a cause, including phones ringing, computer printers and even the crinkling of aluminum foil.
Completely ending those sounds in your home would be very difficult, and it’s hard to judge the severity of the problem because there’s no rating or labelling of ultrasonic emissions on consumer electronics.
Still, there are things you can do.
Strategies to reduce these sounds include turning off components at the plug when not using them (which has the added benefit of stopping expensive phantom power draw).
You can also set up at least one room in your home as a quiet room, free of most or all electronics, including LED lights.
But some of the worst offenders may be the ones that are hardest to control.
We recorded the sound signature of each component in our sample media room by itself: Two of the clearest ultrasound signatures came from the LED bulb in a table lamp and the 42-inch LCD TV on the wall.
Flicker: The disco that never stops
It’s not just unheard noise your pet may be dealing with but also unseen light flicker.
LED lighting is taking over the home, with 40 per cent of the A$33.8 billion LED lighting market going to domestic residences as of 2016, according to Zion Market Research.
But LED lights have the inherent problem of flickering on and off all the time, whether dimmed or at full brightness.
You may barely detect flicker from a modern LED bulb, but as with sound, your pets have a greater range of perception.
Add a disco ball to that high-pitched whine.
David Wren, managing director of PassMark Software in Sydney, blames LED bulb flicker on cheap parts.
LED bulbs are DC devices that run on household AC wall power which must be converted before it feeds the LEDs in the bulb.
In most bulbs, the electronics that perform that conversion do a crude job, with flicker as a by-product.
In humans the critical flicker fusion (CFF) threshold, or the frequency at which a light appears to be completely steady to the observer, can be as low as 24 Hz or 24 “flickers” per second.
Most online video is based on 30 frames per second.
To the human eye, that degree of “flicker” appears to be fluid, smooth motion.
But as Alexandra Horowitz writes in her book Inside of a Dog: What Dogs See, Smell and Know, canines have a more sensitive CFF of up to 80 Hz or 80 flickers per second.
“This might explain why most dogs cannot be planted in front of the television to engage them,” she writes.
“It doesn’t look real.”
Going flicker-free
Here, as with ultrasound, the exact effects of light flicker on pets are unknown, but research has provided some clues.
Dr Richard Inger at the University of Exeter says that “flickering light can have detrimental effects on a number of other animals, so it’s certainly possible that flickering light might have detrimental effect on cats and dogs.”
And a 2006 study by Southwick’s Zoo in Massachusetts and Sacramento City College in California found that a flickering light may cause fear in animals.
Unless you’re planning to move off the grid, you aren’t going to banish the sound and light polluting technologies from your home.
But with so many people just starting to adopt smart home tech in particular, there are fresh opportunities to err on the side of our pets in an area that isn’t fully understood.
You can have the home theatre of your dreams, energy-saving LED lighting and a smoke detector that you can monitor from your phone, but consider your pets in the process.
Remember, they live there, too.
* Brian Cooley is Editor at CNET. He tweets at @briancooley.
This article first appeared at www.cnet.com/.
