"Sound Therapy and Cancer" by Lisa Bakewell (Associated Bodywork & Massage Professionals) https://www.abmp.com/textonlymags/article.php?article=2074 
Grimal and Maman In 1981, biologist Helene Grimal partnered with composer Fabien Maman to study the relationship of sound waves to living cells.
With a camera mounted on a microscope, the researchers observed uterine cancer cells exposed to different acoustic instruments (guitar, gong, xylophone) and the human voice. Using the nine note Ionian Scale (C-D-E-F-G-A-B-C-D), they observed that cancer cells lost structural integrity when exposed to sound until they exploded at the 14-minute mark. Far more dramatic was finding that the sound of a human voice destroyed cancer cells at the 9-minute mark.
Dr. Mitchell Gaynor Mitchell Gaynor, MD, founder of Gaynor Integrative Oncology, board certified medical oncologist, former director of medical oncology at the Weill Cornell Center for Complementary and Integrative Medicine, and author of The Healing Power of Sound (Shambhala, 2002), began using sound as a complementary therapy for cancer patients in 1991 with “remarkable results.”
According to Gaynor, “After either chanting or listening to certain forms of music, immunoglobulin—an index of your immune system, goes up. There’s no part of our body not affected.” Even our heart rate and blood pressure are lowered with certain forms of music, according to Gaynor.“It affects not only our soul and our spirit” Gaynor says, “but it affects us on literally a cellular and subcellular level.”
Anthony Holland Anthony Holland, associate professor and director of music at Skidmore College in New York, uses sound frequency to attack cancer cells.
According to Holland, destroying cancer cells using sound vibration is based on the same principle that a piece of glass shatters when it’s exposed to a noise at the right pitch. Using this principle, Holland and his team wondered if they could recreate the same effect in a living cell.
During their 15-month study, the team discovered a particular combination of two related frequencies that could completely shatter cells. The frequencies consisted of one high and one low. The high frequency had to be 11 times higher than the low, which in music is known as the 11th harmonic. At this frequency, cells start shattering like crystal glass. Using this sound therapy method, they found that pancreatic cancer cells shattered at frequencies of 100,000–300,000 hertz. They then tested the frequencies on leukemia cells and were able to shatter them before they could even divide.
Not only were cancer cells killed in the process, but cancer cell growth rates slowed by over 65 percent. They also had success in attacking ovarian cancer cells.

"Understanding Sound" by US National Parks Service - https://www.nps.gov/subjects/sound/understandingsound.htm

Frequency, sometimes referred to as pitch, is the number of times per second that a sound pressure wave repeats itself.
A drum beat has a much lower frequency than a whistle, and a bullfrog call has a lower frequency than a cricket.
The lower the frequency, the fewer the oscillations.
High frequencies produce more oscillations.
The units of frequency are called hertz (Hz). Humans with normal hearing can hear sounds between 20 Hz and 20,000 Hz.
Frequencies above 20,000 Hz are known as ultrasound.
When your dog tilts his head to listen to seemingly imaginary sounds, he is tuning in to ultrasonic frequencies, as high as 45,000 Hz.
Bats can hear at among the highest frequencies of any mammal, up to 120,000 Hz. They use ultrasonic vocalizations as sonar, allowing them to pursue tiny insects in the dark without bumping into objects.
At the other end of the spectrum are very low-frequency sounds (below 20 Hz), known as infrasound. Elephants use infrasound for communication, making sounds too low for humans to hear. Because low frequency sounds travel farther than high frequency ones, infrasound is ideal for communicating over long distances.

Amplitude is the relative strength of sound waves (transmitted vibrations), which we perceive as loudness or volume. Amplitude is measured in decibels (dB), which refer to the sound pressure level or intensity. The lower threshold of human hearing is 0 dB at 1kHz.
Moderate levels of sound (a normal speaking voice, for example) are under 60 dB.
Relatively loud sounds, like that of a vacuum cleaner, measure around 70 dB. When workplace sound levels reach or exceed 85 dB, employers must provide hearing protection.
A rock concert, at around 125 dB, is pushing the human pain threshold.

Decibels are measured on a logarithmic scale, so an increase of 10 dB causes a doubling of perceived loudness and represents a ten-fold increase in sound level (Crocker, 1997).
In other words, if the sound of one vacuum cleaner measures 70 dB, 80 dB would be the equivalent of 10 vacuum cleaners.
Acoustic resources are physical sound sources, including both natural sounds (wind, water, wildlife, vegetation) and cultural and historic sounds (battle reenactments, tribal ceremonies, quiet reverence).

Soundscape can be defined as the human perception of those physical sound resources. Like beauty, soundscapes are in the mind of the beholder. The rhetorical question about the tree that falls in the forest may help illustrate this. Because no human is there to hear it, the resulting crash is not a part of the human soundscape. It is however, a pretty significant part of the soundscape of the squirrel standing in the tree's path.

The acoustic environment is the combination of all the acoustic resources within a given area. This includes natural sounds and cultural sounds, as well as non-natural human-caused sounds. The sound vibrations made by our imaginary falling tree, are a part of the acoustic environment, regardless of whether a human is there to perceive them.
Bat echolocation calls, while outside of the realm of the human soundscape, are also part of the acoustical environment. It is therefore critical to take the entire acoustic environment into account when working to protect natural sounds.
Because the acoustic environment is made up of many sounds, the way we experience the acoustic environment depends on interactions between the frequencies and amplitudes of all the sounds.
Sound levels are often reduced or adjusted ("A-weighted"), to match the hearing abilities of a human or given animal. Sound levels adjusted for human hearing are expressed as dB(A)