An ultrasonic humidifier is quieter than a traditional mechanical household humidifier because it doesn't require a fan to operate. Using a high-frequency vibrating metal diaphragm, an ultrasonic humidifier turns water droplets into mist, adding moisture to a space. Ultrasonic devices are designed to be unheard by humans, but to our canine companions they may be intensely loud. Whether your dog can hear your ultrasonic humidifier depends on the frequency of the device's sound waves.
Introducing Ultrasonic Sound Waves
"Ultrasonic” describes sound waves that are higher than humans can hear. Most people can’t hear anything over 20 kHz, but dogs can hear sounds as high as 65 kHz. Particularly high-pitched ultrasonic sounds can be annoying to a dog, thought lower-pitched ultrasonic tones may not bother him at all. It depends on the frequency of the sound. It also depends on the volume or decibel level.
The Frequency Matters
An ultrasonic humidifier's frequency should be listed on the box. A typical dog whistle range is between 16k Hz to 22k Hz. If your humidifier falls in this range, it's likely your dog can hear it -- the humidifier is audible to your dog. The younger your dog, the greater the chance he'll hear higher frequencies -- up to 65 kHz. As he ages, the top range of his hearing diminishes, just as your does as you age.
The Whistle Vs. the Humidifier
Sounds are louder to dogs than they are to humans, and dogs hear sounds more clearly, too. Those facts explain why your dog gets upset when you vacuum. Dog whistles are used as a training tool because they disrupt the dog -- the sound makes them stop what they're doing and respond to the source. A humidifier whose frequency in the dog whistle range is going to disturb your dog.
The Ultrasonic Humidifier and Your Dog
Some ultrasonic devices are designed to stop dogs from barking. Does your dog bark whenever someone knocks at the door or walks by a particular window? Test your dog by performing an action that causes barking. If your dog jumps up and begins barking, per usual, he may be unaffected by the humidifier. If he remains silent, the humidifier may be causing him irritation. Your dog may hunker down, whine or be generally out of sorts, especially if the sound is constant.
Separate Your Dog From the Humidifier
The farther ears are from an annoying sound, the less annoying it is. If you separate your dog from your humidifier, you will likely end the issue. In general, dogs don’t hear dog whistles once they’re 15 to 20 feet from the sound. The same distance should suffice for a humidifier. If possible, secure the ultrasonic humidifier in a room your dog can’t enter and keep your dog at least 20 feet from the entrance. If your dog’s behavior returns to normal, you’ve successfully separated your dog from the ultrasonic sound. If you require a humidifier in your dog’s main living areas, you may want to invest in a non-ultrasonic humidifier, like a steam or impeller humidifier.