NEW YORK • Just listen.
"Bring yourself back to your awareness," said Ms Sara Auster, a self-proclaimed sound healer, after 45 minutes in a ballroom at a hotel in Chicago, where she created vibrations using crystal bowls and tuning forks as well as a traditional Indian accordion, known as a shruti box.
Seventy-five people got up like a gaggle of toddlers being shaken from a nap.
The session, which cost US$30 (S$41), was like many popping up in churches, community centres and even some prisons and hospitals.
The goal, practitioners say, is to use sound to tackle individual and collective anxiety, depression, insomnia and more.
Recently, musicians like Erykah Badu and Icelandic band Sigur Ros have dipped into sound healing.
Over in the tech world, mindfulness in deeply in vogue. In April, Adrian DiMatteo, a musician who has a degree in jazz performance, led a sound bath in Brooklyn for leaders at Instagram.
Some health facilities have taken note as well. Ms Auster has performed for an outpatient psychiatric rehabilitation programme at Harlem Hospital in New York.
Darren Austin Hall, a ceremonial musician and sound healer in Toronto, has performed in the atrium of Toronto General Hospital with a Canadian organisation called Music Can Heal.
Ms Diane Mandle, who has offered sound healing in Encinitas, California, for 19 years, said: "It's not curing, it's healing."
Sound baths are an experience in which a group of people gather, often while lying on a mat, to listen to sounds produced via instruments.
There is no licensing procedure for leading sound baths and though Ms Auster would not say where she received her training, her music background and meditation training are strong influences.
For centuries, various cultures, including South Asian, have used sound as a part of religious ceremonies and prayer, with one goal being to promote meditation.
But what about the promise of healing? "Personally I have an issue with the word 'healer', which is why I turn down a lot of wellness events," Ms Auster said. "There are all sorts of expectations with that label and I don't want to be seen as some magical guru or for people to assume they could not possibly have an understanding of the experience."
Like other forms of music, sound baths bring people together, but with an added meditative element.
One way sound is related to health is through noise pollution: traffic noise, planes flying overhead, loud concerts. The World Health Organisation lists noise pollution as an increasing threat to human health and recently set limits on environmental noise.
A 2013 study of tinnitus, led by Mr David Baguley, a professor of hearing sciences at University of Nottingham, listed acoustic therapy as one of several interventions. However, in December, a review of studies found no evidence of using sound versus placebo for tinnitus.
"Well, the absence of evidence doesn't mean absence of benefit," he noted. "We know that sound has a massive influence on how the brain is organised."
A 2014 study found that for patients being weaned off mechanical ventilation, providing them with sounds of nature significantly reduced agitation and anxiety, as measured through heart rate, expressions of pain and blood pressure, when compared with patients who did not listen to these sounds.
So far, the evidence for sound healing is limited and is aligned with what folk know about the effects of calming music and the benefits of meditation.
Ms Auster also believes that one of the biggest benefits of sound baths is that they facilitate community.
"It's people coming together to release and let go, but in the company of others around them," she added.
"If meditation is taking the stairs, a sound bath is taking the elevator."