Laser vibrometry is a technology that has allowed scientists to significantly expand the areas in which they can research vibrations. Vibration sensors that are mounted onto the object that is being studied have existed for some time, but they have the distinct disadvantage of potentially interfering with the vibrational motion of the item due to the physical contact that is required. Here are a few areas where non-contact vibrometry methods have helped scientists make great leaps in knowledge.
The human ear picks up sound waves in the air and converts the vibrations into signals that our brains can understand as particular sounds. Studying the various parts of the ear that participate in hearing is a perfect application for a laser vibrometer. Scientists can use these tools to take detailed measurements of inner-ear vibrations without having to mount any physical vibration sensors inside the ear.
Scientists have been able to gather more information about how people hear and how to approach treatments for hearing loss. Vibration measurements have contributed to technological advancements in hearing aids as well as prosthetic middle ear devices and implants.
Guitars make music when their strings are plucked or strummed, causing the strings to vibrate at a particular frequency. These vibrations are then amplified within the guitar body, making the music audible at a greater distance from the instrument. The sound waves also produce vibrations in the body materials, and those interactions can affect the quality of sound that comes from the guitar.
Scientists have used laser vibrometry to study the movement patterns of guitar bodies of varying quality levels to understand how different materials affect the music produced by the guitar. With the help of science, instrument makers can explore design variables to help them craft the best instruments possible.
Having the ability to measure vibrations without contact has allowed scientists to study various aspects of the human body. Vibration measurements can indicate various facial muscle patterns that indicate certain emotions, which can help computers better read facial signals.
One medical application of this type of vibrometry is in the neonatal unit of a hospital. Doctors have been able to use vibrometers to measure the breathing rates of premature infants without having to place any instruments inside of their incubators.
Using lasers to measure various types of vibrations has been a great tool for scientists. Applications of this technology range widely across many fields.