It seems every day we find there are adverse effects due to things we use in everyday life. Since ultrasonic cleaning utilizes a form of intense energy, is it possible there are side effects to people near the machines in regards to their hearing? The short answer is no. Let us take a look at how hearing works and why ultrasonic cleaning has no known side effects to hearing.
Ultrasonic Cleaning and the Human Ear
The human ear is an amazing piece of equipment. It takes the vibration of a membrane (commonly known as the ear drum) and translates that vibration into electrical energy the brain can read. This happens as sounds travel down the ear canal and force the ear drum to move.
Human ears are typically said to be able to hear in the range of 20 Hz to about 20,000 Hz or 20 kHz. This means those are the frequencies that are able to make the ear drum vibrate.
Typically damage occurs to the ear due to the power, usually measured in decibels, of the sound coming in at one of these frequencies. The ear is only able to handle so much sound power.
Ultrasonic Cleaning Frequency
Ultrasonic cleaners really only begin to work on their low end, well past the high range of where humans can hear. While some cleaners can operate in the 20 kHz range, most are designed to operate higher.
Operation at higher ultrasonic cleaning frequencies means the waves that are generated are incapable of making the ear drum vibrate when generated. In fact, there are no known effects for frequencies higher than 20 kHz having any effect on human hearing at all.
What is the Noise my Ultrasonic Cleaner Makes?
The noises ultrasonic cleaners make are generally caused by sympathetic frequencies of other parts of the machine. Here is a simple example.
Think about how high frequencies can be used to break glass. What happens there is the sound frequencies cause the glass to vibrate at a high rate. The glass breaks due to literally being shaken apart. The same thing happens in the cleaner.
The noises are due to the parts of the machine, tank walls, tubing and other parts vibrating at the frequencies lower than what are being generated. This noise is like any other industrial noise and can be measured. If the noise in the cleaning room is too loud, ear protection should be worn during operation to prevent damage.
Ultrasonic energy is used by medicine as a way to see things in the body that would normally not be seen. It is used in some cases as a safe alternative to x-rays, known to cause damage to the body.
You should not be concerned about the health effects from ultrasonic cleaning. The energy used to make your parts come clean in solution has no known effects on your hearing or other parts of the human anatomy.
