Sound healing is the use of specially crafted sounds in an attempt to induce positive spiritual or medical effects. Sound healers claim to allow listeners to expand consciousness, "repair DNA", or alter brainwave states, among many other claims. While studies using EEG and various neuroimaging techniques have shown that meditation may alter brainwave activity, sound does not and cannot alter DNA.
 Leonard Horowitz
Leonard Horowitz is one of the more famous sound healers around, best known for his popularization of the frequency 528 Hz, part of a series of nine "solfeggio frequencies." In his book, he makes many grandiose claims about the number and frequency, calling it "the universal LOVE constant," "central to Divine creation," "linked to the heart of everything." His evidence for 528's magic is a rapid-fire of pareidolic insanity:
- 5 + 2 + 8 = 15, 1 + 5 = 6, 6 is sacred.
- A mile is 5280 feet.
- 528THz is green, the color of grass.
- The movie Inception involves Room 528.
- The golden ratio is indicated by the symbol φ, which is the initial of the Greek word φιλία, which in English is LOVE, and 528 is the universal LOVE constant.
- Pi is related to the golden ratio because you can divide a circle into five equal sections.
Despite the incoherent logic and handwavey babbling that is his work, Horowitz and his solfeggio frequencies (396, 417, 528, 639, 741, 852, created via numerology) are incredibly popular. You can find lots of hour-long 528 Hz DNA-repair spiritual meditation vibration relaxation videos on YouTube; people enjoy them because the music itself is soothing, not necessarily the tuning system used to derive it.
On the repairing of DNA, Horowitz claims that the 528 Hz sound wave produces healing electrons. This is a misunderstanding of sound and physics. Sound is merely a propagation through a medium or alternating pressure waves and does not produce electrons. Further, if it did produce electrons of the right energy, they would cause damage instead of repairing it (see beta radiation for a physics lesson on this).