Auditory hallucinations occur when you seem to perceive sounds without an external auditory stimulus. The medical term for auditory hallucinations is paracusia. While hallucinations of this type can sometimes be associated with medical conditions in the brain, auditory hallucinations may also arise spontaneously in healthy people. Consuming certain foods or substances like caffeine before bed, sleep deprivation, and chronic stress can all cause someone to hallucinate auditory stimuli. People can also hallucinate sounds, voices or music while in a state of deep meditation or during mystical experiences. Finally, auditory hallucinations often occur naturally in hypnagogic states (those preceding sleep or waking), and can be a useful signal that you’ve entered a “mind awake-body asleep” state from which you may be able to slip into a wake-induced lucid dream.

What defines an auditory hallucination? Well, hallucinations are different from dreams because they take place in external, objective space (instead of a subjective dream world) and seem to mimic real sensations— in this case, sounds. While many people think of hallucinations as seeing things that aren’t there, you can hallucinate any sensory stimulus. People have reported hallucinating tastes, smell, hearing, and tactile sensations including pain movement and body position. Auditory hallucinations are among the most common, and often occur naturally as part of the hypnagogic state: as we fall asleep, our brains filter out the sensory information coming from our bodies, and this awake-asleep transition can sometimes give rise to false sensory information.

There are two categories of auditory hallucination: elementary and complex hallucinations. Elementary auditory hallucinations consist of simple sounds such as hisses, whistling, and banging. As you might expect, complex auditory hallucinations are more complicated sounds such as music, multilayered tones, or voices, which often address the person experiencing the hallucination.

The causes of auditory hallucinations can be as varied as the phenomena themselves: while hallucinations of this type are classically associated with schizophrenia and other psychoses, people suffering from organic brain disorders like temporal lobe epilepsy, chronic diseases like lupus and multiple sclerosis, and endocrine disorders can also experience auditory hallucinations. These false perceptions can also result from the abnormal firing of neurons in Broca’s area, the part of the brain responsible for processing speech and language. If this all sounds kind of scary, don’t worry: there are also many benign explanations for auditory hallucinations. Besides occurring naturally during hypnagogia, you may also hallucinate sounds if you are under stress, eat certain foods before bed, or are trying to get to sleep while overtired. In fact, in people who are suffering from sleep deprivation auditory hallucinations can be one of the earliest indications that they need more rest. States of deep mental concentration or relaxation may also give rise to auditory hallucinations— and if you’re interested in the practice of lucid dreaming or astral projection, that’s a very useful thing.

Like other hypnagogic sensations, auditory hallucinations indicate that you’re falling into a deeper state of physical relaxation; they can alert you that you’re falling into the twilight state immediately preceding sleep. This “brain awake-body asleep” state is the ideal condition for achieving a wake-induced lucid dream or an out-of-body experience. Some practitioners have actually trained themselves to induce auditory hallucinations to lull their bodies into a pre-sleep state while keeping their minds relatively awake. However, I’ve discovered mostly by accident that whenever I try to focus on my hypnagogic sensations— whether auditory hallucinations, kinesthetic sensations, or visuals—they fade away or stop completely. Sometimes I’ve accidentally woken myself up by tuning in too closely to these hypnagogic sensations.

With that in mind, I believe the best way to take advantage of your hypnagogic sensations is to not pay direct attention to them. If you can, try to keep your hypnagogic sensations in soft focus at the periphery of your attention (I’ve found it’s easiest to do this with hypnagogic visuals). Once these sensations have faded or disappeared, you’ve probably entered that coveted twilight state where your body thinks it’s asleep. At this point, you may feel a strong urge to roll over. Stay still: this is your body testing to see if it’s really asleep. Instead of moving— which will break the deep physical relaxation you’ve achieved— concentrate on focusing your mind through guided visualization, breathing, or repeating your intention to achieve a lucid dream.

On the other hand, there are reasons you may want to decrease the frequency of your auditory hallucinations: for instance if they’re making it difficult for you to get to sleep or if you find yourself hearing them in the daytime. First of all, make sure they aren’t a symptom of one of the medical conditions listed above. You may want to consult a physician if you’ve experienced an increase in auditory hallucinations or been hearing them in the daytime. Once you’ve ruled out a medical explanation, you may want to ask yourself if something in your lifestyle could be the cause. The number one cause of non-pathological auditory hallucinations is stress combined with sleep deprivation or reduced quality of sleep. You’re much more likely to start hallucinating sounds when you’re overtired and stressed. Find ways to reduce your daily stress level and maintain good health, such as building physical exercise into your schedule, eating a well-balanced diet, and getting adequate sleep. Herbal sleep aids like valerian, chamomile, and passionflower can be an enormous help if you have trouble getting to sleep. Try reducing your caffeine intake or avoiding caffeinated beverages like coffee altogether as you normalize your sleeping habits, as caffeine can ultimately interfere with falling and staying asleep at night. Also, a recent study has suggested that consuming an amount of caffeine equivalent to five cups of coffee (a moderate dose) may induce daytime auditory hallucinations in people who are also under moderate stress.

Auditory and other sensory hallucinations are a fascinating phenomenon that can offer us a window on how our brains process information at the boundary between wakefulness and sleep. Whether you want to decrease your auditory hallucinations to achieve a faster and more restful sleep, or use them as a jumping off point to achieving a lucid dream, developing a greater awareness of your auditory hallucinations and their triggers can train you to achieve deep sleep more quickly and have more interesting dreams within it.