Binaural-beat perception originates in the inferior colliculus of the midbrain and the superior olivary complex of the brainstem, where auditory signals from each ear are integrated and precipitate electrical impulses along neural pathways through the reticular formation up the midbrain to the thalamus, auditory cortex, and other cortical regions.[6]
After one month of using Equisync, I feel relaxed, calm and not stressed at all, despite that I am leaving my present job soon for an early retirement, I handle the situation very well. I have the feeling that I’m going to be ok and there is nothing to worry about. This is what I have gained so far from using Equisync and it’s really meaningful in the erratic world that we live in.
Brainwave entrainment is a field of study and endeavor founded in the same physiological and psychological processes that make music, drumming, and chanting so powerful as methods for transforming the mind and spirit and aiding in healing of the body. These processes involve how the electrical energy in our brains synchronizes with sounds and visual stimuli, producing a particular brainwave frequency and its associated mental states. 
So my question is: Why? When I read it, I had a bit of a fear of brain aneurysms. Therefore, 1. could someone contact me to tell me why use of your product shouldn’t continue past 2 hours? [I probably won’t heed the reason unless it’s a life or death warning: I love this product that much!] 2. Please feel free to post my letter in your testimonials, if you ever decide to post such customer comments.
I have read something different about theta waves and learning languages. A University of Washington study tested students resting brainwave activity before learning French. They found that students with a higher amount beta/gamma and a lower amount of delta/theta activity were better at acquiring a second language. When you are dominant in theta, that is the lowest and most deeply relaxed awakened state you can be in. I think it would be much harder to really concentrate, fully understand and learn new information while in a theta state, so I would personally consider using theta while studying.
Thanks for the reply. I am now clearer on ‘what’ is heard. Can you expand or point me in direction ..a bit more about ‘pitch frequency’ and frequency spoken about and what exactly is the difference ..and how we use the higher pitch frequencies to ‘hear’ or become aware of them? Would you only pick up the low freq on a EEG?. sorry for being pedantic ..it still does not clear up split isochronics and possibly creating same situation as binaural beats..
I received my order on Mon. and have done 3 or 4 sessions of Equisync I. I just wanted to say I can already notice a difference in myself. I am much calmer and more clear thinking already in just 2 days. I don’t think it’s my mind playing tricks on me. Is this a common occurrence? Your product is great I can’t wait to try Equisync II and Equisync III.
"When these people talk of religious experience, they are talking of a meditative experience," said John Haught, a professor of theology at Georgetown University. "But religion is more than that. It involves commitments and suffering and struggle ­ it's not all meditative bliss. It also involves moments when you feel abandoned by God." "Religion is visiting widows and orphans," he said. "It is symbolism and myth and story and much richer things. They have isolated one small aspect of religious experience and they are identifying that with the whole of religion."
Brainwave Power Music dedicates ourselves to creating original sound therapy music, using unique Musical Compositions, Binaural Beats and Isochronic Tones as our primary sound elements mixed with different instruments and soundscapes to create a relaxed audio environment. We have one main goal: To help others through our music, be it for physical, emotional, mental or spiritual purposes. We constantly upload new music, and continue to work hard to provide new quality music for everyone.
Your brain cells reset their sodium & potassium ratios when the brain is in Theta state. The sodium & potassium levels are involved in osmosis which is the chemical process that transports chemicals into and out of your brain cells. After an extended period in the Beta state the ratio between potassium and sodium is out of balance. This the main cause of what is known as "mental fatigue". A brief period in Theta (about 5 - 15min) can restore the ratio to normal resulting in mental refreshment.  

I love your tapes! I bought them a few weeks ago and have greatly benefited. I’m also a holistic practitioner and have recommended them to a number of patients. And today when I made my last referral to your website for them to purchase from, it occurred to me that perhaps you have referral discounts, or wholesale prices for practitioners, and that I should ask?
Once you have a good recording, start listening to your binaural beats while in bed, and try to be sure you’re undisturbed so your brain can sync up. If you have chronic insomnia, be sure to listen on a regular basis so you train yourself to fall asleep at the same time every night. If you like, you can even invest in a pair of comfortable sleep headphones.
All brainwave frequencies are useful and beneficial at certain times – there is no brainwave that is intrinsically better than another. However, by deliberately choosing to attain a particular brainwave state, a corresponding mental state can be brought about at the same time. For example, a working person who has been in an overly alert beta brainwave pattern for many hours can quickly shift their mind and body into a relaxed state by listening to a few minutes of brainwave entrainment music for inducing alpha or theta brainwaves.
Beta – Throughout the day our brains are in the beta range with a frequency of about 13hz and up. At this level we are active, busy, and all our emotional responses are at this level. People who are over active, or often depressed, irritable, angry etc., often lose out on the recuperation and recharging that takes place when we are relaxed in the alpha, theta, and delta levels.
I would like to share with you my experience after using EquiSync for three weeks. First of all, I am so amazed how fast I can put myself in a meditation state. During meditation, I feel some kind of a sensation I could not explain. I feel the rain dropping on my face and sometimes my legs. I feel the breeze of a tropical weather as if I was in the forest. I always sleep for a very short time at night and I have a very high sense of smell all my life. Using equisync I still sleep less, but am more relaxed when I wake up. During meditation, I can also smell the forest as if I am in the forest.

♥ I found the Binaural Beat Machine to be my #1 focus tool. I have ADD/ADHD and am too easily distracted when I really want to focus. I turn on the binaural beats using the 16b preset for focus and turn down the volume so it's just barely present to my ear. I couple it with some classical music and am able to focus on what I want for extended periods. This literally has changed my life. Thank you!!
Hi. This article contains a lot of information about brainwave entertainment. Thanks. I have a question. I downloaded an Android app that plays isochronic tones. I like to use an Isochronic tone at 2.5Hz that is in Delta range and is supposed to help me get a deep and dreamless sleep. I use it without headphones and just keep the smartphone next to my pillow. But I do not know if I should keep the tone playing all the time while I sleep or put it on timer to shut off after some specified time. A custom timer is possible with the app. Can you please guide me.
Scientists and clinicians use brainwaves to measure and understand the functioning of the brain. We typically can’t see them, but human brains have billions of neurons. These individual neurons connect to thousands of other neurons. And when brain activity happens, these neurons light up much the same way thousands of audience members do “the wave” in an arena.
(Shannahoff-Khalsa, 1991; Webb & Dube, 1981). These naturally occurring shifts may underlie the anecdotal reports of fluctuations in the effectiveness of binaural beats. External factors are also thought to play roles in mediating the effects of binaural beats (Owens & Atwater, 1995). The perception of a binaural beat is, for example, said to be heightened by the addition of white noise to the carrier signal (Oster, 1973), so white noise is often used as background. "Music, relaxation exercises, guided imagery, and verbal suggestion have all been used to enhance the state-changing effects of the binaural beat" (Owens & Atwater, 1995). Other practices such as humming, toning, breathing exercises, autogenic training, and/or biofeedback can also be used to interrupt the homeostasis of resistant subjects (Tart, 1975).
In the meta-analysis performed by Fox et al., several sources of bias were indicated which bring into question the validity of meditation studies which use neuroimaging. Fox et al. suggests a publication bias may be leading to the over-reporting of significant results.[18] Despite this, however, Fox et al. found "consistent differences in prefrontal cortex and body awareness regions" in "areas key to meta-awareness..., exteroceptive and interoceptive body awareness..., memory consolidation and reconsolidation..., self and emotion regulation..., and intra- and interhemispheric communication..." and that changes were significant with "moderate" global median effect size and "consistent and medium-sized brain structure differences."[18]
Binaural beats by themselves are dull for some people to listen to. But with nature sounds or ambient music, as well as either white noise, pink noise, brown noise, mixed in with the binaural beats it is more pleasant to listen to longterm. Normally it will take about 6 minutes for the brain to start becoming entrained by the binaural beats. But it is best to listen to binaural beat recordings daily that are any where between 10 minutes to an hour long.
The pitch frequency measures and describes what a beat sounds like, i.e. does the isochronic beat have a deeper bass sound, or is it high pitched and sharper sounding? The beat waveform frequency describes how many times the beat is repeating per second, i.e. how fast it is beating. You don’t really need to concern yourself about the pitch frequency, as that doesn’t have a direct influence on brainwave entrainment and doesn’t play a part on the measurement on an EEG. I only mentioned it because you were referring to humans not being able to hear below 20Hz. I change the pitch frequency just to suit the mood of the track. For tracks that are to be relaxing, for meditation or sleep, I tend to use a lower pitch frequency so it sounds deeper and more relaxing and I never have that lower than 100Hz. For an energizing, high focus track I might use a more higher pitched 200Hz isochronic tone, because that is sharper sounding and less likely to make you feel sleepy. That’s all you really need to know about the pitch frequency.
Hello Jason, this is an unusually thoughtful discussion. Thank you for all your expertise and your kind manner of presenting and moderating it. I’m wondering if you have any experience with this: ever since I’ve been exposed to theta wave music, without headphones, I have found it irritating. And this is in spite of the fact that when I was first handed a CD by someone I knew well and trusted he was so confident I’d love it It didn’t occur to either of us that I might not. This happened again recently, which is about 10 years later, when I heard it playing overhead at an acupuncture clinic. I felt restless and even irritated, unable to zone out, which is unusual for me, during the treatment. I realized that the quality of my irritation was similar to what I’d felt listening to that CD a decade ago.So I asked if it was theta wave music and she said yes. The acupuncturist said that some people, but a vast minority, really dislike the music. She said that the few people who dislike it are not simply neutral, but actively dislike it. And she also said, but most people like it a lot. I’m just wondering what kind of factors might be present that would make a person feel so irritated by this music?
Other research by Paul Ekman, of the University of California San Francisco Medical Center, suggests that meditation and mindfulness can tame the amygdala, an area of the brain which is the hub of fear memory. Ekman discovered that experienced Buddhists were less likely to be shocked, flustered, surprised or as angry as other people. Flanagan believes that if the findings of the studies can be confirmed they could be of major importance.

Many studies on mindfulness meditation, assessed in a review by Cahn and Polich in 2006, have linked lower frequency alpha waves, as well as theta waves, to meditation.[4] Much older studies report more specific findings, such as decreased alpha blocking and increased frontal lobe specific theta activity.[5] Alpha blocking is a phenomenon where the active brain, normally presenting beta wave activity, cannot as easily switch to alpha wave activity often involved in memory recall. These findings would suggest that in a meditative state a person is more relaxed but maintains a sharp awareness. Two large, recent comprehensive review works, however, point to poor control and statistical analyses in these early studies and comment that it can only be said with confidence that increased alpha and theta wave activity exists.[4][6]

So, there’s the deep stuff here, and then there’s the gamma stuff, too. There’s a little bit of 80 Hz, but it’s primarily a 40-Hz gamma track, gamma frequencies that are combined with a pulse, on and off, throughout the recording. I went to some lengths to make this as rich and potent as I could, whilst blending it into the sound of the music. There are these really rich, kind of cat-purr-like vibrations that come through at times, combined with the lulling, deeply relaxing theta brain waves.
Belief and faith, argue believers, are larger than the sum of their brain parts: "The brain is the hardware through which religion is experienced," said Daniel Batson, a University of Kansas psychologist who studies the effect of religion on people. "To say the brain produces religion is like saying a piano produces music." At the Fuller Theological Seminary's school of psychology, Warren Brown, a cognitive neuropsychologist, said, "Sitting where I'm sitting and dealing with experts in theology and Christian religious practice, I just look at what these people know about religiousness and think they are not very sophisticated. They are sophisticated neuroscientists, but they are not scholars in the area of what is involved in various forms of religiousness."
Hi i’m just writing to let you all know that your Equisync CD’s are amazing! Just last night i was meditating to “Equisync II”. The one that has mostly theta binaural beats in it. I gotta tell you i have never had a meditation like i experienced with this CD. At certain points during the meditation it felt like my whole damn body was vibrating! That very night when i went to sleep I also had lucid dreams! It was so relaxing! I’ve tried “Equisync I” too, that one is amazing as well! I haven’t tried “Equisync III” yet. I can only imagine what that is going to be like!
In 1984 medical researcher Dr. Gene W. Brockopp published a paper making several conclusions of audio and visual entrainment (AVE). Such conclusions were that hemispheric synchronization caused by AVE is related to increased intellectual functioning, practiced use of AVE overtime leads to a cumulative effect, and AVE may result in the recovery of early childhood experiences.
The most common way to use a brainwave entrainment is for a short-term benefit, to help guide your brain into a particular mental state at the time you need it.  In a similar way to how you might take a sleeping pill before bed to help you get to sleep, or maybe drink some coffee or an energy drink to help wake you up and give you a boost of energy.

As to the second question raised in the above paragraph, audio with embedded binaural beats alters the electrochemical environment of the brain. This allows mind-consciousness to have different experiences. When the brain is entrained to lower frequencies and awareness is maintained, a unique state of consciousness emerges. This state is often referred to as hypnogogia "mind awake/body asleep."  

However, yoga and meditation take time to learn and master, and until the student becomes proficient, progress can be slow and frustrating, leading many people to abandon the effort before they see the benefits. Brainwave entrainment has the potential for helping a person enter the relaxing and rejuvenating mind-states brought about by yoga and meditation without the learning curve and time needed for mastering these other techniques. Brainwave entrainment may even facilitate learning other mindfulness methods by helping a person achieve success faster and more reliably. 
The objectives and inclusion criteria of the review were clear. Relevant sources were searched for studies, although the restriction to published studies in English meant that the review was prone to publication and language biases. The authors did not state whether steps were taken to minimise the risk of bias and error in the processes of study selection and data extraction (for example, by having more than one reviewer independently make decisions). The authors mentioned which studies were blinded, but it did not appear that study validity was systematically assessed, which made it difficult to judge the reliability of the review findings. The decision to combine studies by narrative synthesis appeared appropriate given the strong clinical heterogeneity between the studies, but the authors failed to quantify the size or statistical significance of the findings reported. The evidence presented appeared to justify the authors’ conclusions that further research was justified, but in view of the dearth of good-quality evidence and problems with methodology and reporting in the review, the conclusions regarding efficacy did not appear reliable.
I’ve been using equisync first thing in the morning after I get up, and listen to all three tracks in a row. I again listen to all three tracks in the late afternoon. If I don’t have that much time available, I will start on Track 2 or 3, as necessary. I have really started to focus on my breathing, and notice the difference – I finish the session in a DEEPLY relaxed state.
This app offers an easy to use interface that helps you achieve certain states of mind for different activities. From headache treatment to IQ boost to Sleep Induction and Relaxation, this app offers frequencies for over 25 scenarios. If you’re looking for an app that will let you choose a state of mind or activity and then just hit play, this app would be great to use.

Isochronic tones have only been proven to have an effect while you are listening to them, that’s why you won’t find me claiming anywhere that there are potentially positive long-term effects. Once the tones stop, your brainwaves are no longer being stimulated by the sound and so they stop being in sync with the tone frequency. For you to think you are still feeling the effects after all this time and from such a short time listening to them, I think it may be linked to anxiety. I know that some people who are new to this type of thing can build up a strong feeling of anxiety, after worrying about the potential effects brought on by fear of the unknown. I suspect the problem may be psychological with you worrying about the potential effects and keep repeating the experience from memory in your head. When you keep going over the same thing in your head like that and worrying about it, it’s easy to then spot other potential side-effects like how your nostrils and body temp is feeling, then making links back to that experience and labelling that as the reason. I think the best way to overcome this is to realise that the side-effects you are mentioning are completely unrelated, so there is nothing to worry about. These tracks are literally listened to for millions of hours a month on YouTube across loads of channels. If the effects lasted for a long time people would just listen for 5 minutes and come back in a couple of weeks. But people keep coming back to listen because that’s the only way to feel the benefit and effects…while you are listening to them. If you are unable to stop thinking and worrying about this on our own, I recommend that you speak to your doctor about it or a specialist in dealing with anxiety issues. I hope that helps.

The Alpha state is an intensely pleasurable and relaxed state of consciousness, essential for stress reduction. Alpha is associated with deep physical and mental relaxation, but not quite meditation. Alpha waves instill a sense of mild euphoria, calm your body, reduce Cortisol levels, strengthen your immune system and counteract the negative effects of stress. Alpha waves also increase the production of Melatonin to greatly improve the quality of your sleep.
Binaural beats are acoustically generated frequencies that match the frequency bands of brain waves and are therefore considered a means to inducing neurophysiological relaxation. There is, however, large dispute on the scientific quality and validity of extant research on binaural beats. Thus, the effect of a binaural 10Hz (Alpha) stimulation on subjective and physiological parameters... [Show full abstract]
The power and manifold benefits of meditation are well documented, its practice dating back to prehistory where it was used mainly for religious or spiritual purposes. With our growing knowledge and understanding of the functions of the brain it seems both logical and practical that we should develop ways of tapping into this power and using it to our advantage.
Brain wave entrainment is a real phenomenon and is useful as one method of investigating how the brain works. But there is no evidence, nor any theoretical basis, for any long lasting effect on brain function or that there is any benefit of any kind. Despite this, there is a huge industry of devices that claim to train your brain waves and have a beneficial effect. I wouldn’t waste a dime on any such device.
Many psychologists, doctors, teachers, and other professionals have endorsed the technology while personally taking advantage of the limitless benefits that accompany EquiSync's precisely designed brainwave synchronization/ entrainment technology. It is such a profound field of study that many of the metaphysical benefits, those beyond our current scientific measure and technological & philosophical understanding, have yet to be discovered.
Uses of audio with embedded binaural beats that are mixed with music or various pink or background sound are diverse. They range from relaxation, meditation, stress reduction, pain management, improved sleep quality, decrease in sleep requirements, super learning, enhanced creativity and intuition, remote viewing, telepathy, and out-of-body experience and lucid dreaming. Audio embedded with binaural beats is often combined with various meditation techniques, as well as positive affirmations and visualization.
Theta: This brainwave pattern is associated with deep relaxation and with some stages of sleep, including the lighter stages of non-REM (NREM) sleep. REM sleep itself is mostly composed of beta wave and other activity that’s similar to an alert, waking brain. Deep meditation produces theta waves, which are slower and lower frequency (between 5-8 hertz) than Alpha waves. That murky barrier between sleep and wakefulness, when you’re drifting in and out of sleep, and your thoughts feel dreamlike and difficult to remember? That’s a theta-dominant state of consciousness.
I first became aware of brainwave meditation programs  and brain waves when researching alternative methods for treating the bipolar disorder I had been unsuccessfully living with my entire adult life. I eventually learned a method of releasing difficult emotions on the spot, which I then practiced extensively, and consequently found it easier and even desirable to meditate for fairly lengthy periods of time. Though I took up meditation as a serious daily practice and experienced many undeniable benefits, I nonetheless intermittently experienced life-debilitating bouts of mania and severe depression, often resulting in chaotic mixed states and an inability to maintain daily social functions. During these times, it became nearly impossible to sit in meditation.
I’m working as a consultant for a new and growing holistic wellness company. I am responsible for determining which products would be the most advantageous for both our patients and for retail sales. I have personally purchased the Equisync I CDs to test them. My daughter suffers from major anxiety. The CDs helps her to relax and be less anxious. I tried it myself one time and it was very effective at putting me into a deep meditative state. I believe that your product works and I would like the wellness company to carry Equisync for patients to use and purchase.
During meditation, people often feel a sense of no space. Scientists investigating the effect of the meditative stateon Buddhist monk's brains have found that portions ofthe organ previously active become quiet, whilst pacified areas become stimulated. Using a brain imaging technique, Dr. Newberg and his team studied a group of Tibetan Buddhist monks as they meditated for approximately one hour. When they reached a transcendental high, they were asked to pull a kite string to their right, releasing an injection of a radioactive tracer. By injecting a tiny amount of radioactive marker into the bloodstream of a deep meditator, the scientists soon saw how the dye moved to active parts of the brain.
^ Bittman, B. B., Snyder, C., Bruhn, K. T., Liebfreid, F., Stevens, C. K., Westengard, J., and Umbach, P. O., Recreational music-making: An integrative group intervention for reducing burnout and improving mood states in first year associate degree nursing students: Insights and economic impact" International Journal of Nursing Education Scholarship, Vol. 1, Article 12, 2004.
Theta brainwaves in the frequency range of 6 to 9 hertz are known as thalpha waves because of their proximity to alpha waves. They are seen during states of high suggestibility, during hypnosis, and during paranormal experience and are also connected to an increase in human growth hormone (HGH) levels and higher blood flow to the brain. Theta brainwaves sit between the realms of the subconscious and conscious mind, making them an especially useful brainwave state for developing creative thinking, working through emotional problems, and integrating subconscious and conscious experience. 

So does that mean that there are certain types of brainwaves that are better? The short answer to that question is that each brainwave has a different function. During the day, you might want to produce a certain kind of brainwave more frequently or during different times and activities. That requires a certain amount of control, flexibility, and resilience.
In the meta-analysis performed by Fox et al., several sources of bias were indicated which bring into question the validity of meditation studies which use neuroimaging. Fox et al. suggests a publication bias may be leading to the over-reporting of significant results.[18] Despite this, however, Fox et al. found "consistent differences in prefrontal cortex and body awareness regions" in "areas key to meta-awareness..., exteroceptive and interoceptive body awareness..., memory consolidation and reconsolidation..., self and emotion regulation..., and intra- and interhemispheric communication..." and that changes were significant with "moderate" global median effect size and "consistent and medium-sized brain structure differences."[18]
A common element in recordings incorporating alpha and theta frequencies is a steady but barely perceptible rhythm of the frequencies themselves. This subtle and calming pulse mixes with sounds of gentle breezes, distant bird songs, and the slow progression of deep synth notes. Underneath this, below the audible sounds at sub 16 hertz levels, other frequencies intermingle, deepening the merging of conscious and unconscious mind.
Synchronized brain waves have long been associated with meditative and hypnogogic states, and audio with embedded binaural beats has the ability to induce and improve such states of consciousness. The reason for this is physiological. Each ear is "hardwired" (so to speak) to both hemispheres of the brain (Rosenzweig, 1961). Each hemisphere has its own olivary nucleus (sound-processing center) which receives signals from each ear. In keeping with this physiological structure, when a binaural beat is perceived there are actually two standing waves of equal amplitude and frequency present, one in each hemisphere. So, there are two separate standing waves entraining portions of each hemisphere to the same frequency. The binaural beats appear to contribute to the hemispheric synchronization evidenced in meditative and hypnogogic states of consciousness. Brain function is also enhanced through the increase of cross-collosal communication between the left and right hemispheres of the brain.
Some studies have found that binaural beats can affect cognitive function positively or negatively, depending on the specific frequency that’s generated. For example, a study of long-term memory found that beta-frequency binaural beats improved memory, while theta-frequency binaural beats interfered with memory. This is something for scientists to continue to examine closely. For people who use binaural beats, it’s important to understand that different frequencies will produce different effects.
The phenomena of brainwave entrainment was first described in the scientific literature in 1973 by Gerald Oster in results published in an article in Scientific American entitled, “Auditory Beats in the Brain”. He showed that a specific brainwave could be induced when a person heard two separate, but closely related, sound frequencies, one in each ear. He discovered that when the frequencies heard by each ear differed by about 10 hertz, the brainwave pattern of the person hearing the sound would synchronize to the difference between the two frequencies. For example, if the person heard a 410 hertz sound in one ear and a 400 hertz sound in the other ear, their brainwaves would stabilize at the difference between the two, or 10 hertz. This technique is called binaural beats, and it is a fundamental principle of brainwave entrainment methods.

Research done under Gerald Oster suggested that binaural beats may be used as a medical tool, especially for diagnosing neurological conditions. In particular, he noticed that untreated sufferers of Parkinson’s disease were unable to “hear” binaual beats but further research indicated successful treatment when the subject was finally able to perceive them at the end of a Parkinson’s treatment regimen. Oster also noted difference in perception in women based on their menstrual cycle, and posited that there may be some connection between the ability to perceive binaural beats and the woman’s levels of estrogen at the time.
Earlier evidence out of UCLA suggested that meditating for years thickens the brain (in a good way) and strengthens the connections between brain cells. Now a further report by UCLA researchers suggests yet another benefit. Long-term meditators have larger amounts of gyrification ("folding" of the cortex, which may allow the brain to process information faster) than people who do not meditate. A direct correlation was found between the amount of gyrification and the number of meditation years, possibly providing further proof of the brain's neuroplasticity, or ability to adapt to environmental changes.
This phenomenon is best known in acoustics or music, though it can be found in any linear system: "According to the law of superposition, two tones sounding simultaneously are superimposed in a very simple way: one adds their amplitudes".[2] If a graph is drawn to show the function corresponding to the total sound of two strings, it can be seen that maxima and minima are no longer constant as when a pure note is played, but change over time: when the two waves are nearly 180 degrees out of phase the maxima of one wave cancel the minima of the other, whereas when they are nearly in phase their maxima sum up, raising the perceived volume.
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