How loud is too loud for a dog?

Every grooming tool sold now claims to be quiet. Almost none of them say what they mean by it, and the ones that print a number rarely say where it was measured from.

Here is enough to judge for yourself.

The number on the box

Sound is measured in decibels, and the scale is not linear. Every increase of ten decibels is roughly a doubling of perceived loudness.

For a sense of scale:

• 30dB a quiet bedroom at night
• 50dB a fridge humming in the next room
• 60dB normal conversation
• 70dB a vacuum cleaner in the same room
• 85dB the level at which humans are advised to wear ear protection

A standard pet clipper runs somewhere around 60 to 70dB. A forced air pet dryer is frequently 85dB or higher. Anything under about 50dB is genuinely quiet, and that is the number worth looking for.

Why the number understates it for a dog

Two things make this worse for dogs than the figures suggest.

They hear much higher frequencies. Human hearing tops out around 20,000Hz. Dogs continue to around 45,000 to 65,000Hz. Small motors produce a great deal of high frequency whine that we barely register and they hear clearly. A tool that sounds like a gentle hum to you can be a piercing noise to them.

The tool is against their skull. A decibel figure is usually measured a metre away. A clipper working around the ears is a few centimetres from the ear canal, and the sound is conducted through bone as well as air. The number on the box is not the number your dog experiences.

Vibration is a separate problem

Owners focus on noise because that is what they can perceive. Dogs often object to vibration more.

A dog being clipped feels a buzzing sensation through their skin continuously for as long as the tool is on them. Some dogs never stop finding that strange. This is why a dog can be completely relaxed about the sound of a clipper running on the other side of the room and still object the moment it touches them.

If your dog is fine with the noise and objects to contact, you have a vibration problem, and a quieter motor will not fix it on its own. Shorter passes with breaks in between will.

How to test a tool before you trust it

Turn it on and put it on the floor across the room. Watch the dog rather than the tool.

Ears pinned back, head turned away, freezing in place, licking lips, or leaving the room are all a no. A glance and then disinterest is a yes. This takes thirty seconds and tells you more than any specification.

Do that before the tool ever touches them. Every dog that has been ambushed by a noise while being held will remember it.

The practical threshold

If you are choosing between tools and you cannot hear them first, treat these as the rules of thumb:

• Under 50dB is quiet enough that most dogs will tolerate it near their head.
• 50 to 60dB is usable on the body, and worth avoiding around the ears.
• Above 70dB you should expect a reaction from any dog who is not already thoroughly used to it.

The quietest tool you will tolerate using is almost always a better purchase than the most powerful one, because the powerful one gets used twice and then lives in a drawer.