Listening for the Logos:
a study of reports of audible voices at high doses of psilocybin
Horace Beach, Ph.D.
Kaiser Permanente Medical Center
Department of Psychiatry
Chemical Dependency Recovery Program
For an updated list of psilocybin studies,
There are reports that psilocybin mushrooms can engender a dialogue
between the one who ingests them and a voice of unknown origin. The
objective of the present study was to search for such reports, to look for
differences between those who reported having heard a voice with
psilocybin use and those who had not, and to characterize the voice. An
anonymous questionnaire was distributed among the members of several
organizations resulting in a sample of 128 participants. The phenomenon of
a perceived voice during psilocybin mushroom use was reported in better
than a third of participants.
Overall, the results of this study suggest that what made the difference
between hearing a voice or not with psilocybin was more about what people
did, than who they were. Can it be said that there are boundaries to the
human psyche? Psilocybin voice experiences force us to confront our
notions of a personal self and a universal Self.
For a copy of this thesis contact:
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P.O. Box 1346
Ann Arbor, MI 48106-1346
tel: (313) 761-4700
There are a number of verbal and literary reports that psilocybin (or
"psilocybian") mushrooms speak to human beings - that is, they
can engender or catalyze an auditory dialogue between the one who ingests
them and a voice of unknown origin. T. McKenna terms this
"interiorized linguistic phenomenon" an experience of the Logos.
The Logos is to be understood as a sort of intermediary between what one
might consider to be God, the Truth, or the "Suchness" of
reality, and human beings. While it is possible to experience directly the
Absolute, or noumenon of phenomena, or the Nondual, much of recorded
historic experience of what has come to be known as divine inspiration or
revelation comes through one of the various manifestations or
intermediaries of the Absolute in the form of gods, spirits, angels, or
ancestors. The daimon of Socrates is a good case in point; for example,
Angeles states that in Plato's Symposium "the daimon communicates to
the gods the prayers of humans and reveals to humans the commands of the
gods." At times these intermediaries of the Absolute appear to
humans, but they also reportedly can be experienced as disembodied voices.
While it can be argued that the voice, or voices, may ultimately be
"some previously hidden and suddenly autonomous part[s] of one's own
psyche" (T. McKenna, 1991b), such discussion can lead one into the
philosophical abyss of what is ultimately meant by "one's own
psyche" and the concept of self and other. Nonetheless, the voices
many times present themselves as quite alien.
Persinger and his colleagues at Laurentian University are looking at
"Other," "ego-alien intrusions," or a "sensed
presence" phenomena from a neurophysiological perspective. In the
search for brain correlates to the experience of "presences,"
their studies have focused primarily on the deep temporal lobe structures
of the brain, the amygdala and hippocampus, which Persinger characterizes
as the most electrically unstable structures in the human brain. There
are three major points to be gleaned from Persinger's work relevant to the
auditory voice phenomena reported by individuals taking high doses of
psilocybin. First, the numerous reports studied by Persinger that involve
an ego-alien experience or a sensed presence are similar to reports of the
otherness or alienness of the experience of the Logos. Second, that the
temporal lobes are implicated in Persinger's correlational studies is
highly suggestive, as the role of the temporal lobes in normal and
so-called hallucinatory audition is well known. Third, Persinger's focus
on melatonin is interesting because melatonin production in the pineal
gland is accomplished through the conversion of serotonin by the enzyme
HIOMT. Thus, any compound that affects the serotonergic system (as
psychedelics do), and is reported to elicit a sense of an alien other with
auditory voice phenomena, must be explored with an eye toward Persinger's
findings. Psilocybin fits the bill on both points. However, while the
investigation of neurochemical correlates is a vital piece in the
understanding of Logos-like phenomena, it is not true that by describing
the neurochemical correlates of any mental activity one has found its
explanation. Perhaps the relationship between the brain and its
neurochemical correlates to the experience of mind should best be thought
of as an interface with, or receiver of, mind (Sheldrake, 1989). Wilber
views the brain as an exterior aspect or manifestation of the mind and
consciousness. In any case, trying to understand the mental effects of the
psilocybin experience solely in terms of physio-chemical factors entirely
misses other levels of comprehension.
Potency and Dosage
Due to species variation, psilocybin mushrooms differ in potency. For
example, concentrations of psilocybin in Psilocybe cubensis is about 2
mg/gm, whereas the quite potent Psilocybe semilanceata averages around
12.8 mg/gm in fresh specimens. Potency can also vary between strains of
the same species, or even between various mushroom "flushings,"
or fruitings of the same mycelial organism (mushrooms are the sexual
organs, so to speak, of the underground living web organism known as a
mycelium). One therefore has to estimate average amounts and percentage
concentrations when dealing with mushroom psilocybin and psilocin.
Fortunately, there are some general agreements. Most sources cite
psilocybin's entheogenic or psychedelic effects in humans as occurring
between 5 and 50 milligrams, with the highest reported human dose at 120
milligrams and the "maximum safe dose" around 150 milligrams
(Ott, 1993). A consensus of opinion favors a "high" dose of
psilocybin to be at least 12 milligrams, or five or more dried grams of
well-preserved Psilocybe cubensis mushrooms for a 154-160 pound person.
There is some discussion, however, concerning whether mushrooms containing
psilocybin differ in their effects from pure synthetic psilocybin, aside
from the effects of the synthetic generally lasting a shorter time. In any
case, it was understood by the researcher that the amount of psilocybin
and psilocin varies between mushroom species, making sheer comparisons of
number or weight crude at best, and it was hoped that the species-based
psilocybin/psilocin content variation would be randomly distributed
throughout the study's sample and therefore not a source of bias.
T. McKenna conducted a survey that was highly influential in the
development of this study, in that its results suggested that the audible
voice phenomenon was dosage-related. He has also stated that for some
individuals, as much as 9.5 grams of dried mushrooms are required to
elicit a voice, and also that other conditions and techniques may be
necessary to hear a voice. Though there are a number of different types of
voice experiences, the common thread running through them all is the
imparting of information to the listener. This is the crucial importance
of voices. In traditional usage, the mushroom voices give healing
information. While there are many reports of experiences with psilocybin
that do not include the phenomenon of voices, it should be noted that
"the Indians recognize that it is not to everyone that they
speak" (Munn, 1976). Perhaps they do not speak to one for a number
of reasons: poor mental set, the lack of a technique to elicit a voice,
poor environmental setting, old or improperly stored mushroom material
weakening the psychoactive effects, insufficient dosage, psilocybin
mushrooms versus synthetic psilocybin, poor absorption in the stomach,
idiosyncratic body chemistry, mental experience, a person's sensory input
style, or not enough experiences with psilocybin (use over time may deepen
the experience, as with LSD in psychotherapy) (Grof, 1985, 1988).
While not a voice, another reported auditory experience with tryptamine
compounds, especially psilocybin, is what has been described as a
"buzzing" sensation or sound. Discussion of this peculiar audile
phenomenon may not be so far afield from the focus of the present study.
Gordon (1993) has suggested that tinnitus (a condition of ringing,
buzzing, hissing, or humming in the ears) from any cause can trigger
auditory hallucinations of music, or even speech.
There are a few provocative and suggestive findings in the literature.
However, these should be examined with the admonition, as previously
discussed, that to the detriment of understanding, "it is so easy to
replace the word "mind," in our inquiries, with the word
"brain" (Alexander Shulgin & Ann Shulgin, 1992). A common
denominator in the biochemical research with psychedelics in general, and
with tryptamines in particular (psilocybin/psilocin), is that, somehow,
the neurotransmitter serotonin is specially involved in the psychedelic
experience. Of particular interest to this study is research suggesting
that serotonin may have a special role in the perception of inner
(subjective) auditory experience (Andorn, Vittorio, & Bellflower, 1989,
Hegerl & Juckel, 1993).
Psilocybin is an "agonist[ ] or partial agonist[ ] at several
subtypes of the serotonin (5HT) receptor: 5HT-2, 5HT-1c, and 5HT-1a"
(Strassman, 1992, p. 241), and the chemical structure of psilocybin's
metabolite, psilocin, is close in structure to serotonin. While this may
suggest a reason for the general psychoactive effects of psilocybin and
psilocin, it cannot solely account for the tryptamine, psilocybin-specific
auditory voice phenomenon. The reasons for this are many. As already
stated, serotonergic neurotransmitters and receptors are strongly involved
in the psychoactive effects of many of the psychedelics, including, for
example, the phenethylamines; yet reports of voices are absent in one
major work on phenethylamine compounds (Alexander Shulgin & Ann Shulgin,
1992). It is also not enough to say that the auditory effects of
tryptamines are the result of their having a unique structure in
comparison with other psychedelics: for example, it can be pointed out
that LSD and other of the ergolines "can [also] be viewed as rigid
tetracyclic tryptamines" (Nichols, 1986, p. 338). If tryptamines,
particularly psilocybin, are shown to have specific and somewhat unique
abilities to stimulate auditory voice phenomena in human beings, their
mere similarity to serotonin is not sufficient explanation. However, the
serotonergic system is somehow specially involved in auditory experience,
as is Brodmann areas 41-42 in the temporal cortex and Broca's area (P.
McGuire, Shah, & Murray, 1993).
Demographics of the Sample
There were several sources of participants for the study: subscribers to
the MAPS Newsletter, the membership of The Fane of the Psilocybe Mushroom
Association, the subscribership of The Entheogen Review, and the Internet.
The final sample consisted of 128 participants who had returned useable
questionnaires. Ninety-nine males and 29 females ranging in age from 18 to
75 (M = 40.72, SD = 12.86) made up the study. Judging by postal marks,
participants hailed from at least 31 states and 8 foreign countries. Of
these individuals, 106 designated Caucasian as their primary ethnicity,
followed by Jewish, with six, and one of each for 13 other ethnicities.
The average years of education for the group was just over 16, or the
equivalent of a Bachelor's degree (M = 16.48, SD = 2.52). Based on the
responses to the question of the number of times psilocybin was taken, the
study examined approximately 3,427 reported psilocybin experiences (n =
118). Of the total questionnaire responses (N = 128), 35.9% (n = 46) of
the participants reported having heard a voice(s) with psilocybin use,
while 64.0% (n = 82) of the participants stated that they had not. Based
on the responses to the question of the number of times [they] experienced
a voice(s) with psilocybin, the study examined approximately 394
experiences of psilocybin-induced voices (n = 40). Each item on the
questionnaire was designed to be treated as a separate variable to be
compared between groups or correlated within a group. Because of the
skewness of some of the distributions, and in some cases due to the type
of data collected, all comparative and correlational data for the study
were analyzed using nonparametric statistics. Also, exploratory and
confirmatory subgroups were utilized.
Differences Between the "Yes" and "No" Voice(s)
True to T. McKenna's suggestions for how to increase the possibility of
voice experiences with psilocybin, the group that reported having heard a
voice(s) with psilocybin use (the Yes group), on average, took the
mushroom more times, took a larger amount of dried grams of mushrooms per
use, and took the mushroom more often in darkness than the No group. In
fact, the average reported dried grams of psilocybin mushrooms taken per
experience for the No group is less than the average minimum amount of
dried grams of psilocybin mushrooms needed to hear a voice(s), as reported
by the Yes group. The Yes group also used psilocybin and then tried or
intended to hear (evoke) a voice(s) more times than did the No group.
Curiously, and not predicted by T. McKenna, the Yes group reported using
psilocybin mushrooms grown themselves more often than the No group. One
may speculate that the care and attention required by mushroom cultivation
might contribute to a greater intention to hear a voice(s), thus leading
to a more successful evocation. There were two findings of statistically
significant differences between the Yes voice(s) and No voice(s) groups.
First, the Yes group reported taking psilocybin more often while alone
than the No group. This could have also been predicted by T. McKenna's
suggestions of technique. By being alone, talking is eliminated as a
distraction. It must be that the phenomenon of a voice(s) is subtle
enough, at least initially, as to be missed due to exterior (talking,
light) or interior (lack of intention) distractions. Namely, the voice(s)
does not present itself to the "bemushroomed" person simply
because he or she ingested a certain amount of psilocybin. Although, as
many participants suspected (according to comments written on the
questionnaires), larger average doses may be one of a number of factors to
account for the presence or absence of the voice(s) experience. The second
statistically significant difference between the groups was the finding
that those in the Yes group endorsed having heard a voice(s), at least
once, when using drugs other than psilocybin significantly more often than
did the No group. In other words, those participants who heard voices with
psilocybin also tended to hear voices while using other drugs. It is
interesting to note that the descriptions of these voices were not so
different from the descriptions of voices heard while using psilocybin.
These results tend not to uphold the theory that psilocybin is somehow
unique in its ability to catalyze or elicit voice phenomena, and yet a
majority of the participants who reported hearing a voice(s) through
psilocybin and other drugs or means indicated that they first heard a
voice(s) with psilocybin. Perhaps for those individuals, psilocybin acted
as a catalyst that opened a door to the subtle experience of the voices,
which then allowed them to experience the voices by other means. Also it
should be noted that, by far, the most popular answer as to which drugs
other than psilocybin also catalyzed voices was LSD, followed by DMT and
mescaline. LSD and DMT are similar to psilocybin in that they can be
classified as serotonin-like-and even though mescaline can be classified
as catecholamine-like, its psychedelic effects can probably be represented
in terms of changes in serotonergic neurotransmission. Thus, the
suggestive connection between drug-catalyzed voice(s) phenomena and
serotonergic neurotransmission, discussed earlier in this article, appears
again. Of T. McKenna's technical suggestions for eliciting a voice(s),
only two were not supported: First, the admonition not to eat a full meal
within the six hours before taking psilocybin (in fact, the No group, on
average, did this less often). The second is his suggestion that cannabis
may aid the hearing of voices. In only 17.4% of total voice(s) experiences
with psilocybin (n = 34) was it reported that it was helpful to take any
other drug(s) with psilocybin to hear a voice(s) - but, in agreement with
T. McKenna, of the few who responded in the affirmative, cannabis was the
most popular choice.
A number of crude measurements of personality were attempted in this
study. An examination was made of introverted and extraverted attitudes,
remembering dreams, having lucid dreams, meditating, "Type A
personalty," and "repressive coping style." However, the
groups were not found to differ significantly on any of these facts. Also,
a number of personal beliefs were examined: religious belief, belief in
spirits, belief in precognition, belief in life after death, and personal
health assessment. On none of these beliefs was this study able to show a
repeatable, statistically significant, difference between the Yes and No
groups. A number of possible sex differences were also examined and none
were discovered. It seems that men were not experiencing significantly
more male voices than women, and women were not experiencing significantly
more female voices than the men.
Overall, the results of this study suggest that what made the difference
between hearing a voice or not with psilocybin was more about what people
did, than who they were. Better than one third of participants' reported
experiences with a voice(s) and psilocybin involved some form of
evocation. That evocation was not reported to occur 100% of the time prior
to hearing a voice(s) may indicate that evocation was not always
necessary, or that perhaps after a participant evoked the voice(s) in some
way in his/her early experiences, it was no longer always necessary to do
so with later voice(s) experiences.
It was not reported very often that there was more than a single voice
heard during an experience. Additionally, it was found that the voice
experience cannot be maintained for long periods of time (average reported
length of time was about 19 minutes).
A look at those characteristics endorsed as occurring, on average, in more
than 50% of reported total experiences with a voice(s) and psilocybin, may
also help to describe trends that characterize the voice(s). The
experience of the voice(s) is generally reported as positive, insightful,
and useful. Though evidently a subtle phenomenon, the voice(s) is reported
most of the time as clear-sounding and sensible. The experiences of being
able to communicate with the voice(s), and gain information, were also
reported to occur in over half of the episodes. These facts tend to lend
credence to the theory that the voice(s) may be experiences of a
Concerning the more specific characteristic tendencies of the voice(s),
those who have experienced the phenomenon describe the following features
as occurring in most of their experiences: First, the voice(s) usually
sounded old. This is consistent with the findings of at least one other
source (Oss & Oeric, 1991). Second, the voice(s) usually sounded male.
Third, the voice(s) was usually described as low-pitched (bass-like), slow
paced, and of low volume. It is interesting to note that at least one
other tryptamine compound has been found to alter (lower) the perceived
pitch of externally-generated voices and music, DIPT, or,
N,N-diisopropyltryptamine (Alexander Shulgin, personal communication,
January 25, 1996). One additional point: in a little less than half of
reported experiences, participants stated that the voice(s) expressed
emotion; compassion, anger, love, calm, humor, fear, and sadness were
most often reported.
Other features of the voice(s)
Emphasis of the "otherness" of the voice(s) pervades the
phenomenological descriptions given by many of the participants, and is
also borne out by some of the statistical data. In just under half of
reported experiences, participants had the sensation that the voice(s)
came from outside of their heads. A majority of participants also stated
that the voice(s) was not familiar when they first heard it with
psilocybin. A few participants even commented that although it was their
own voice they heard, the "information" was not from them.
Finally, in just under half of reported experiences, participants said
that the voice spoke in first person. Interestingly, this occurrence was
highly correlated with the participants receiving insight from the
voice(s). It may be that the experience with an other who is an I (who
witnesses, reflects, communicates, shares) facilitates insight, much as
in psychotherapy (Frank, 1989). One of the most interesting findings of
this study is that in over 45% of participants' total experiences with a
voice(s) and psilocybin, sounds other than voices were present. Notice
should be given to the words used by a number of the participants: high
pitch, high tone, humming, buzzing, whirring, ringing, rustling, rushing
water, howling, vibrations, whooshing, crinkling, insect-like, drumming,
whirling-circular. These reports are similar to observations made by T.
McKenna and D. McKenna (1993), Strassman, Qualls, Uhlenhuth, & Kellner
(1994) and Weil (1980). It may very well be that, as Gordon (1993)
concluded, a condition of ringing, buzzing, hissing, or humming in the
ears, from any cause, can trigger auditory hallucinations of music, or
even speech. For example, one participant reported that he heard voices
when a motor (lawn mower) was running. An interesting side note: use of
Heimia salicifolia (sinicuiche), a plant that contains the alkaloid
cryogenine or vertine (Ott, 1993), has been reported to cause a ringing in
the ears that then turns into orchestrated music. The many reports of the
Yes voice(s) group hearing other sounds are consistent with a theory that
these sounds may be involved in the hearing of a voice(s).
It may be that the Logos (as Mind) superimposes itself on, and utilizes,
the formless white-noise of internal (tinnitus, for example) or external
(drumming, rattles, motors, running water, glossolalia) stimuli, to create
a voice(s), and then, entering the individual's faculty of audition,
speaks. Meaning (form) is superimposed on the formless.
So what does it mean?
My study lends credence to the theory that psilocybin inspired voices are
expressions of the Logos. Beyond that, what the Logos is, well, that
depends on how "Eastern" your world view is. That is, when
people ask me what I think these voices may be, whether part of us or not,
I have to first ask them what the mean by "us." The question of
what is self and what is other then takes prominence. Is there anything
that we can say is truly alien? Though in our experiences we may encounter
a "Wholly Other," from an Eastern perspective (or in the
ancient West, a Plato-Plotinian one) all of the Cosmos is interior to us.
Can it be said that there are boundaries to the human psyche? Psilocybin
voice experiences force us to confront our notions of a personal self and
a universal Self.
This article is based upon my Clinical Psychology doctoral dissertation
entitled, "Listening for the Logos: A study of reports of audible
voices at high doses of psilocybin," which was produced at The
California School of Professional Psychology at Alameda. I wish to
acknowledge my chairperson, Fred Leavitt, Ph.D., and my committee members
Norm Livson, Ph.D., and Alexander "Sasha" Shulgin, Ph.D. Special
thanks to Sylvia Thyssen, Networks Coordinator for MAPS, and Rick Doblin,
MAPS President, who were the first to agree to distribute my questionnaire
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