It's no secret that anxiety plagues patients as they go through the uncertainty of healthcare treatments. Anxiety can also be exacerbated by medical circumstances such as drug use, phobias and mental disorders. Typical hospital environments don't make it easy for a patient to relax. The beeps of various medical machines, bustling hall noises, even the distinctive smells that waft through a clinical setting are enough to cause tension in a patient.
There are many techniques to help a patient relieve stress, from breathing techniques to encouragement and distractions, but one often-overlooked element is the power sounds can have on the human mind, specifically, sounds from nature.
The gentle burbling of a brook, the steady sounds of waves or the whistling of the wind in the trees have the ability to physically change our brain chemistry and bodily systems, helping us to relax no matter where we are.
Natural sounds and environments have been anecdotally linked with relaxation and well-being for hundreds of years. Recent studies suggest that science backs these claims and can even physiologically impact healing and recovery after a stressful event.
Nature sounds reduce the reactionary "fight-or-flight" signals in the brain.
In a study published in Scientific Reports in March 2017 researchers reported their findings on the physiological effects of naturalistic sounds versus artificial sounds utilizing brain scans, heart rate monitors and behavioral experiments.
When nature sounds were played the results were associated with a decrease in the body’s sympathetic response —the “fight-or-flight” feeling— and an increase in parasympathetic response — the response that tells the body to relax and function in normal circumstances. 
Nature sounds speed up recovery
Research has also demonstrated that listening to nature sounds helps you recover faster after a stressful event. In a study conducted in 2010, test subjects were given a stressful problem to solve and once they completed it the speed of nervous system recovery was measured by skin conductance levels (SCL) with electrodes.
"[The] detailed analyses of the recovery functions showed that half-life SCL recovery was 9−37% faster during the nature sound than during the [other] noises." 
Background nature sounds can ease patients into restful sleep.
Sudden noises, even at low volume, disturb restful sleep because our minds are hardwired to alert us when it perceives a threat. In a healthcare setting, many machines are designed to alert caregivers when something is wrong, unfortunately that simultaneously can prevent patients from entering into the deep sleep they need to recover.
One study found, "In a hospital setting, alarms played as low as 40 decibels, roughly the volume of a whisper, were found to awaken participants from shallow sleep 90 percent of the time. For people in deep sleep, this volume would wake up them half the time." 
Noise machines help work as acoustic camouflage to the ear and mask the interruptive noises designed to alert medical staff.
"These slow, whooshing noises are the sounds of non-threats, which is why they work to calm people. It's like they're saying: 'Don't worry, don't worry, don't worry.' Having a masking form of noise can also help block other sounds you don't have control over, whether someone is flushing a toilet in another part of the house, or there are taxis or traffic outside — whatever the acoustic insult is" 
Help patients easily access nature sounds from their patient television.
The PDi A-Series Enhanced Entertainment TVs offer pre-installed nature sounds to help patients relax. With a few navigational clicks on the pillow speaker, the patient can switch from regular TV programming and fill their room with the sounds of rushing streams, relaxing waves or dripping rain to help ease any tensions they may be feeling, and drown out any disruptions from other sounds in their surroundings.
1. Cassandra D Gould van Praag, Sarah N. Garfinkel, Oliver Sparasc, Alex Mees, Andrew O Philippides, Mark Ware, Christina Ottovian, Hugo D. Critchley; 'Mind-wandering and alterations to default mode network connectivity when listening to naturalistic versus artificial sounds'; Scientific Reports volume 7, Article number: 45273 (2017); https://www.nature.com/articles/srep45273
2. Jesper J Alvarsson, Stefan Wiens,Mats E Nilsson; 'Stress Recovery during Exposure to Nature Sound and Environmental Noise'; NCBI (2010) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2872309/
3. Cheyenne Macdonald,'Why the sound of water helps you sleep: Study reveals how non-threatening noises are blocked out by the brain'; DailyMail (2016) http://www.dailymail.co.uk/sciencetech/article-3405747/Can-t-sleep-Listen-sound-WATER-Study-reveals-non-threatening-noises-help-brain-switch-off.html#ixzz5H5HDtKQW
4. Adam Hadhazy; 'Why Does the Sound of Water Help You Sleep?'; LiveScience (2016); https://www.livescience.com/53403-why-sound-of-water-helps-you-sleep.html