Why the Male Voice Dominates Auditory Hallucinations

Have you ever experienced hearing a voice in your head showing you right from wrong, your conscience, the real life Jiminy Cricket? Or have you had the slightly humiliating experience in a noisy crowd where you go ‘Yes!’ assuming someone has called out to you? These are a few examples that can be paralleled to the experience of auditory hallucinations heard by schizophrenic patients although the actual phenomenon is a much more complex one. The occurrence of auditory hallucinations, or false perceptions of voices, has fascinated many who have chosen to study it, and has disturbed and tortured many others who claim to have actually experienced it.

Auditory hallucinations are one of the main symptoms of schizophrenia. Research has shown that the majority of people who have been subjected to this kind of hallucination, claim to have heard male voices as opposed to female voices. This comes as quite a surprise since female voices are the first voices babies recognize and they are the comforting voices heard during childhood and while growing up. Voice perception is a very important part of a human being’s identification process since it helps one to determine the gender, personality and much more about a person. A person’s voice helps another person identify and recognize them without seeing them and also helps in determining the mood of a person. Most auditory hallucinations heard by schizophrenic patients are those of anger, which tell the person of destructive acts such as committing suicide. One could assume that the early recognition of the female voice during childhood would result in it attracting the attention of the brain. I am confused then as to why it is that the supposedly more captivating female voice isn’t generated when people hear these false voices in their heads?

Sound travels in waves and vibrations which are channeled through the outer ear and through the ear canal. The vibrations bump against the ear drum resulting in the movement of bones in the middle ear which transfer the vibrations to the cochlea in the inner ear. The fluid in the cochlea vibrates the tiny hairs, or cilia, which stimulate the auditory nerves. The auditory nerves transfer the vibration signals to the brain via action potentials and the brain starts to process the sounds in the auditory portion of the brain, which is found in the temporal lobe. This is where an important question arises, how can the brain hear sounds if no sound waves are present to travel to the ear?

The false voices that are heard by the majority of schizophrenic patients are believed to be “caused when the brain spontaneously activates, creating a false perception of a voice"1. One explanation for what causes auditory hallucinations is the dysfunction of neurons in their use of dopamine as a neurotransmitter. It is amazing to consider this self-activation of the brain that is not consciously created by the person, or due to any input/signal. It is also scary to think that you (or some aspect of you, such as the “I-function”) are in control of your movements and your brain only to learn that the brain can automatically create an output without any inputs. This could be a result of corollary discharge. The inability of the person to distinguish between actual spoken words (reality) and internal thoughts shows a lack of perception which could be a due to an error in the corollary discharge system. Auditory hallucinations are one of the main symptoms presented by patients with Schizophrenia. These patients often hear very violent voices during episodes of auditory hallucination and statistics show that over half of schizophrenic patients hear male voices in their hallucinations.

A study was conducted to determine the difference in how the brain processes a male voice versus a female voice. Dr. Michael Hunter, a researcher worked on Professor Peter Woodruff’s team at the University of Sheffield, and conducted a study to determine the differences in the female and male voice. In this study the participants were males, because the male brain presents a simpler model of sound processing. Men use only one half of their brain (the left side) to process voices whereas women use both halves of their brain to comprehend language2. Two experiments were done on a group of men; in one scenario the men were made to listen to voices and had to determine the gender of the voice. Some of the voices were edited to sound more ambiguous. The participants were readily able to determine the gender of the distinctly male and female voices; however the more ambiguous voices created a problem. The participants took longer to determine the voice’s gender and were more often incorrect in their determination. The second study took these same recordings and had the participants listened to the recordings while the scientists scanned the brain using fMRI to see the brain activity. fMRI detects the areas of greatest blood flow in the brain, and it is assumed that the active portion of the brain will require excess blood.

The results of the study found that a female’s voice activates the auditory portion of the brain, found in a region in the cerebral cortex. It is know that the primary auditory cortex is the first portion of the cerebral cortex to receive auditory input. This section of the brain is used to analyze sounds and read voice tones. The male voice was found to activate a portion in the brain known as the mind’s eye, a region located towards the back of the brain. The mind’s eye is a portion of the brain that compares prior experiences to the sequence of events or in this case the voice. So essentially when hearing a male voice the male brain is comparing the voice to his own and determining the gender based on this comparison3.

It is found that the female voice is much more complex than the male voice. This complexity is due to the shorter vocal cords, the smaller larynx, the higher pitch, wider range of sounds, and the more melodious tone of the female voice. The complexity of the female voice offers an explanation for why it triggers the activation of the portion of the brain that requires more analysis of the voice. The male brain may find it harder to process a female’s voice because it cannot compare the wide range and other complexities to his own voice. This added complexity has been concluded to explain the reason that a male voice is heard during auditory hallucinations. The female voice has so much intonation and such a complex range that it is more difficult for the brain to conjure and replicate than a males voice is.

To me this still leaves the question of whether women would hear female voices during auditory hallucinations more often than a male voice. It seems that if a woman heard a female voice it would be processed through the mind’s eye because the voice would be compared to theirs to determine the gender. If the female voice is detected by women in the mind’s eye portion of the brain rather than the auditory cortex it would seem that a women would find it easy to replicate a voice similar to theirs. However this may suggest the women’s brain being more developed than men’s, because it is able to replicate a complex sound, and this claim about the brains cannot be made. It could simply be that the female brain may comprehend a female voice more easily than the male brain because the voice is more similar and easy to relate to their voice; however generating a false female voice will be just as difficult for the female brain, because the brain will have a hard time replicating the complexity of the voice.

The complexity of the female voice may not be the only reason as to why the brain replicates a male voice during an auditory hallucination. I think that through social stereotypes the female voice is often construed as the more soothing and comforting voice while the male voice is perceived as more authoritative and daunting as well as as the voice of discipline. What is heard during auditory hallucinations are voices that command attention and convey harsh messages so it seems plausible to imagine that it would need a comparatively more intimidating voice to accompany them. For this reason it could be that auditory hallucinations take on a male voice more effectively than a calm comforting female one.

The reason auditory hallucinations occur remains a mystery. How the brain can stimulate a scenario similar to the perception of sound waves without an input is most astonishing, and truly shows the complexity of the human brain. Where the brain is concerned, one can only study behavior and patterns. Deciding on a set conclusion regarding most of the activities carried out by the brain is difficult if not impossible. Although an explanation for auditory hallucinations remains vague, it is seemingly more understandable why a male voice is generated rather than a female voice, at least in a male brain. Further research in the future will probably be able to shed more light on the process a woman’s brain uses to generate male voices during episodes such as an auditory hallucination. We can only hope that more extensive researches carried on in this field will help us come to a solid conclusion so that it can be used to aid patients suffering from delusions to overcome their disorders.

Resources

1. http://news.bbc.co.uk/2/hi/uk_news/education/4675103.stm

2. http://www.audiodesignline.com/news/168601986

3. http://www.emaxhealth.com/85/2805.html

4. http://sciencepolitics.blogspot.com/2005/08/sex-on-brain-of-science-reporters.html

5.http://www.sciencedirect.com.proxy.brynmawr.edu/science?_ob=ArticleURL&_udi=B6WNP-4GFV5ND-3&_user=400777&_coverDate=09%2F30%2F2005&_rdoc=10&_fmt=full&_orig=browse&_srch=doc-info(%23toc%236968%232005%23999729996%23604190%23FLA%23display%23Volume)&_cdi=6968&_sort=d&_docanchor=&_ct=22&_acct=C000018819&_version=1&_urlVersion=0&_userid=400777&md5=ebea79d48381a665090573f881748757

6. http://en.wikipedia.org/wiki/Auditory_system

7. http://www.freepatentsonline.com/6430443.html