An exploration of the principles of psychoacoustics
When it comes to the subjects of hypnosis music, the principles of psychoacoustics leap to the front of my mind. These are the principles that I take into account whenever I compose therapeutic music for hypnosis or meditation.
You may already know a lot about psychoacoustics without even realizing it. This article will help to clarify some of the science behind what you already know on an intuitive level and it will give you some great insight into what types of music work best for relaxation and hypnotic induction.
What is psychoacoustics?
psy•cho•acous•tic / adjective
“A branch of science dealing with the perception of hearing and sensations produced by sound”.
In other words, psychoacoustics is the study of the ways in which sound affects you emotionally, physically and mentally.
You could think of it as a form of music psychology.
It’s Not All Science!
Even though psychoacoustics is a science, I won’t be bogging you down with charts and graphs on this page and I certainly don’t want to give you the impression that hypnosis music is something that can be neatly summarized by a set of scientific principles! First and foremost, music is an art form.
Science can help us to understand, on an intellectual level, how and why human beings respond to music as they do, but science can never fully explain the magic of music any more than the science of cardiology can explain the mystery of love.
Helen Keller put it in her own special way when she said:
“The most beautiful things in the world cannot be seen or even touched, they must be felt with the heart.”
When it comes to creative endeavors like music composition, we must always leave some room for intangible factors – intuition and inspiration will always play a part and will sometimes give rise to music that defies the dictates of logic.
Why Is Psychoacoustics So Important?
Most music composers are perfectly capable of creating relaxing music, but in order to create music that goes beyond “pleasant” – to create music that can actively assist in hypnotic induction and help to keep the listener in a deep state of relaxation requires some understanding of the principles of psychoacoustics, and ideally, first hand experience of altered states of consciousness such as those that we encounter during deep meditation or hypnosis.
This article is hardly a complete summary of the all the principles of psychoacoustics, but rather a casual exploration of how and why certain types of music induce relaxation states.
Before we begin, let’s start by asking a rather simple question…
Why do we listen to music?
The fundamental reason why we enjoy listening to music is because it is mood altering. Music can stir your emotions. It can stimulate or sooth you. It can relieve stress and it can induce stress also.
Have you ever been so touched by a beautiful piece of music that you cried? Have you ever cringed at the sound of fingernails being dragged down a chalkboard? Most people answer “yes” to both of these questions, which just goes to show that music, and indeed all forms of sound, can have a significant effect on your state of mind.
So if sound can have such a strong effect on us, then how can we use this to our advantage? What can the study of psychoacoustics do to help us create music that encourages altered states of consciousness, like those found during meditation or hypnosis?
Some types of music are certainly more relaxing than others. Some sounds are particularly hypnotic, some cause trance – like states, and some types of music, like those containing binaural beats, can even alter the frequency of your brainwaves. Let’s get to know what some of these sounds are and how they are used to create music for deep relaxation…
“Sonic mantra” is the phrase that I use to describe repetitive sounds that are used in place of a traditional meditation mantra. These sounds could be as simple as a metronome’s tick, or better still, they can be musically expressive – a repeating series of notes for example.
Music example: Deep Within
As long as they are tonally pleasing, repetitive sounds can really help to lull the mind of the listener into a state of deep relaxation and they are wonderful for hypnosis or meditation. Music that contains Sonic Mantras is what I sometimes call “true” meditation music, because it embraces the time-honoured technique of using mantras to induce a state of deep relaxation.
Goodness – what a dull sounding word! Sure enough, the idea of drones might sound a bit uninspiring to you at first, but drone sounds can be deeply relaxing and are fantastic for inducing states of deep relaxation and sleep.
What are drones? Drones include any sound that is:
1. Unbroken – the sound does not stop and start, and
2. Relatively unchanging in pitch.
A classic example of a drone-like sound that has been used for meditation for thousands of years is the sound of the “Om” mantra.
Music Example: Om Mantra
Drone sounds usually have no melody, and they have no discernable tempo, but they do have other important qualities that must be musically pleasing. For example, drones often have a texture that can be described with words like “smooth”, “fine”, “soft” or “coarse”, and a timbre that can be described with words like “celestial”, “warm” or “complex” just to name a few.
The pitch of a drone must not be too high or the drone may become shrill and tiring, and it must not be too low or the drone may become aurally opressive and even imperceptible on some stereo systems.
A drone may also be comprised of many layers of sounds, and when these sounds harmonize with each other they become deeply hypnotic and most pleasurable to listen to. Sometimes this effect is very subtle, but when it comes together well the result is sublime. Like a fine wine, drones can be complex, multi layered and immensely satisfying.
I personally am a huge fan of drone music and use it often during my own meditation practice. I have also received a great deal of positive feedback from hypnotherapists who have used my drone music during live sessions and in hypnosis CD productions.
Drones can be listened to “raw”, or they can be used to provide a hypnotic foundation to a piece of music that contains other elements such as chimes, nature sounds or instrumentation. Here is just one example:
Music Example: Ascension
When it comes to music for inducing states of meditation and hypnosis, drones can extremely useful. They tend to envelop the listeners awareness in a very gentle way, especially when played on headphones. Drones seem to fill up the space in your mind and wash away thoughts with their constant, soothing tones. Unlike music that is melodic and dynamic, drones will not overstimulate your mind or distract you while you are in the deepest states of relaxation.
The Sounds of Nature
Since the dawn of time, we have been graced with the wonderful sounds of Mother Nature. It’s only been during the last few decades or so that man-made music has become commonplace…and along with it has come all the noise and cacophony of modern industry and media. We have become cut off from the sounds of our natural environment, and bombarded by sounds that cause stress.
Listening to the sounds of nature reminds us that we are a part of a greater whole. The sound of birds in the morning, the sound of crickets in the evening…these are just some of the sounds that remind us that our life extends beyond the walls that surround us at our home or office. The ebb and flow of waves on a beach, the sound of wind in the trees…these soothing sounds are innately peaceful and have a purity about them that most of us have become disconnected from. Just as some aromas can trigger memories, the sounds of nature can trigger a biological memory within us that reminds us that we are a part of nature itself.
Nature sounds can be used to great effect in many types of relaxation music, especially when they are used to add atmosphere or to emphasize a guided visualization that involves natural scenery.
When it comes to music for hypnosis, nature sounds may be included, but care must be taken not to add sounds that might be distracting. For example, sporadic bird sounds might be an irritation for some listeners, especially if they are played too loudly. On the other hand, the repetitive sound of a cricket’s chirping can be used like a metronome to add a hypnotic element to the music. Again, care needs to be taken to manage the volume and tonality of these sounds so that they are soothing, and never shrill or aurally fatiguing.
Brainwave Entrainment Music
I’m sure that you have already heard of the word “brainwaves” and you may already know that brainwaves can be measured with a machine called an electroencephalograph (EEG).
When you are awake and alert, your brain operates at a higher frequency than when you are drowsy or asleep. An EEG allows us to measure these changes, just as it allows us to measure the brainwave frequency of a person who is in a deep meditation. With this in mind, we come to the whole point of brainwave entrainment music…
Certain sound frequencies, when combined in specific ways, can be used to alter your brainwave activity, thereby inducing various states of relaxation.
Brainwave entrainment is simpler than it might sound at first. Think of it this way…imagine you are holding two tuning forks of the same pitch. If you strike one of them and hold it close to the other, they will both vibrate at the same frequency. Brainwave entrainment or “brainwave synchronization” is similar to this. It relies upon the frequency following response, a naturally occurring phenomenon that explains how the human brain tends to change its dominant frequency towards the frequency of an external stimulus.
As you might expect, brainwave entrainment doesn’t work with any old sound. To give rise to the frequency following response, specific types of sounds must be used. Here is a brief introduction to the two most common types of sounds for brainwave entrainment.
Binaural Beats or “binaural tones” are created by playing two tones of slightly different frequencies – one presented to each ear. When listened to with headphones, they usually sound like a simple humming sound that pulses ever so slightly.
Your brain is very sensitive to small variations in the frequency of sounds, and to the way those sounds reach your ears. So by playing a tone of 200 Hz in the left ear, and 210 Hz in the right ear, a difference of 10 Hz is detected by the brain.
The difference between the two frequencies could be called a “sub harmonic” – a sound that is below the threshold of human hearing. However, this sub-harmonic binaural frequency may still be detected as a slight pulsing sound. This pulsing, or beating, is why we call them binaural “beats”.
Binaural beats cause the brain to adjust its dominant frequency to match the frequency of the beats. This is what is known as the “frequency following response”.
In order to control the way the frequencies reach your ears, music that contains binaural beats must be listened to with headphones. You’ll notice that when binaural beats are played on open speakers, they sound vastly different – the beating sound becomes very obvious when the sound waves from each speaker interact with each other.
Here is an example of a pure binaural tone with a delta frequency of around 1.5 cycles per second. First, try listening with headphones, and then compare this to the way it sounds when you listen on stereo speakers. Provided that your speakers are evenly spaced in front of you and are of a reasonable quality, you should be able to hear a much more pronounced beating sound.
Binaural beats make a wonderful addition to music for hypnosis because they can actively induce a state of deep relaxation. They can also be useful when dealing with dealing with clients who are particularly resistant to relaxing.
In their raw form, binaural beats are rather plain sounding, so they are usually embedded within a piece of music. Drone music makes a perfect home for binaural tones. Here is an example of some drone music with binaural tones:
Music Example: Untold Depths (Delta)
And here is an example of some more melodic music that contains a foundation of binaural tones:
Music Example: Letting Go (Delta)
Like binaural beats, isochronic tones can also used to stimulate the frequency following response.
In contrast to binaural beats, isochronic tones can be listened to without the aid of headphones. Isochronic tones are simply a repetitive pulsing sound that encourages the frequency of your brainwaves to synchronize with the frequency of the pulsing.
Much like the hypnotic effect of a pendulum clock, isochronic tones are a simple but effective way to encourage brainwave entrainment. In the example below a theta frequency of around 7 Hz is used (quicker than the delta frequencies demonstrated above). The effect is subtle but you should be able to hear the quick, pulsing sound of the isochronic tones.
Music Example: The Temple Gardens (Theta)
White noise has a special role to play when it comes to relaxation, but it is often overlooked as a sound-source for inducing altered states of consciousness.
Just as white light is the aggregation of all visible light frequencies, white noise is the sound that is produced when all possible sound frequencies are played at once. It is a pitch-less drone sound. When you think of white noise, you probably think of the nasty hissing sound that comes from your TV or radio when it’s not properly tuned in. In its raw form it sounds like this:
Caution: Play Quietly!
Sounds a bit nasty doesn’t it? That’s white noise all right, but it’s just one type of white noise. The sound of ocean waves – that’s white noise. So is the sound of rain, the sound of wind and the sound of your hairdryer. These are all forms of pitch-less sound that we can categorize as white noise.
Raw white noise can be manipulated – sculpted if you will – to create sounds that are deeply hypnotic. By reducing certain frequencies and modulating the tonality of the white noise over time, raw white noise can be transformed into very soothing sounds that can be quite soporific. Like this for example:
Music Example: Constellation
White noise sounds help to absorb the attention of the listener, but without stimulating any particular emotional response.
White noise recordings have some very practical real world applications. For example, white noise is wonderful for masking background noises, and so many people use white noise as a sleep aid, or to drown out distracting sounds so that they can concentrate on a specific task. White noise can also be used to enhance meditation, to relieve tinnitus, to cure insomnia, and even to prevent eavesdroppers from listening in on private conversations!
A Word on Tempo
Studies have shown that the tempo of a piece of music can have an effect on the respiration rate and heart rate of the listener – a fact that with important implications when it comes to music for hypnosis.
However, I think it is worth mentioning that the importance of tempo is sometimes overstated. I’ve come across numerous websites that boldly claim that “60 beats per minute is the perfect tempo” and that anything other than this particular tempo is unsuitable for hypnosis. I get the impression that this assertion is a flimsy attempt to assert a point of difference; more a marketing tactic than real fact.
In most cases the tempo of any music that you use for hypnosis should be less than 70 beats per minute. Most of the music that I compose will usually fall somewhere between 48 and 65 beats per minute. However, some music has no discernable tempo whatsoever, and in these cases tempo is irrelevant! Drone music is a great example of this.
To Bell or not to Bell? – That is The Question
Relaxing new age music is famous for being laden with bell sounds, chimes and bell-like instruments such as electric pianos. These sorts of sounds sure do add plenty of atmosphere to music, whether they are used instrumentally, or as an occasional feature sound.
However, bells can be distracting to some listeners once a deep state of relaxation has been reached. This occurs for two reasons:
1. Bells (and bell like instruments – even pianos fall into this category) have a short “attack time”, meaning that the sound they make is emitted almost instantly when played. The sudden, percussive nature of bell sounds can be a little intrusive.
2. Bells can be quite shrill and inharmonic, depending on the type of bell that is struck.
These issues are usually not a problem during hypnosis, so long as the composer has been careful to manage the volume and tonality of the sounds that he or she has used.
“After silence, that which comes nearest to expressing the inexpressible is music”. Aldous Huxley (1894 – 1963)
One of the principles that many top masseurs adhere to is “never take your hands off the patient once you start the massage”. Even if the masseur moves to another part of your body, or moves around the table you are lying on, he or she will keep at least one hand in contact with you at all times.
I think of hypnosis music in a similar way. Just like a soothing massage, the music should never fall completely silent and break its bond with the listener. If you start a hypnosis session with music in the background, then keep the music going until the session is complete. If you must silence the music, then fade it out very slowly.
It’s interesting to note that music can be composed in such a way that it impresses the sensation of spaciousness or silence upon the listener, without actually falling silent. This is a highly desirable effect that can really help the listener to sink into a deeper and more open state of mind.
The simplest way to achieve this is through a combination or foreground and background sounds. For example, imagine a soft drone sound (background sound) over which a gentle instrument plays a melodic passage (foreground sound). As a listener, your attention will tend to follow the foreground sound. By allowing the foreground sound to fade out very gently and slowly, the sound that held our awareness a moment ago gradually gives way to an empty space that opens up a gap in the listener’s awareness. The background sound remains – it is ever present – like the unmoving hands of the masseuse, holding the space but never leaving you unaccompanied.
The above explanation takes on even more meaning if you substitute the word “subconscious” for “background sound” and the word “conscious awareness” for “foreground sound”.
Using music in this way is very much a balancing act. The music must provide enough stimulation to engage the listener, but not so much that it becomes a distraction. It must absorb the listeners attention, and then quietly recede for long enough to allow the listener to sink into a deeper state. It’s all about balance…
Hypnosis and Music Therapy – It’s Deep Stuff!
Hypnosis music is sometimes regarded as being “simple”. Sure enough, most hypnosis music is not as complex as say, a full orchestral composition, but like many things in life that appear simple, there is often great care and finesse involved in crafting such an art form.
Music and hypnosis go hand in hand, and as you have by now come to realize, hypnosis music can be a pretty deep subject! Not only is hypnosis music something that you can appreciate on a sensory level, it’s exciting to realize that it can be crafted in such a way that it has a direct effect on the activity of your mind. It is with this excitement that I apply the principles of psychoacoustics to hypnosis music…to bring you the most relaxing music possible.
Christopher Lloyd Clarke B.Sc, Msc.D.
Music composer and founder of Royalty Free Hypnosis Music.com