So I wrote this paper when I was pregnant with my first daughter, and I really loved researching and learning about it so much! Thought it was interesting enough to share, even though technically, it's not violin related.
The earliest signs of ear development begin at approximately 7 weeks after conception. Throughout infancy and through adulthood, the human ear helps us to absorb information and give us a complete picture of our surroundings. The question is to what extent has a newborn already been set up for auditory success? There has been much research into the field of prenatal musical stimulation and while there is no conclusive evidence that prenatal music exposure will turn your unborn into Mozart, the benefits of hearing music during pregnancy may have surprising benefits in many areas.
The start of hearing in the fetus doesn’t seem to be an all or nothing phenomenon. The ear first appears in the 7th week. From 10 weeks the external ear can be seen in ultrasound. At 16 weeks the ear begins to be functional and responds to a sound pulse. From the age of 19 weeks there is responsiveness at 500 hz, and at 20 weeks, along with the ear completing developing cochlean structures, can distinguish between a two second sound pulse to a one second sound pulse. The acoustic nerve enters the brainstem at 24 weeks, Synapses mature between week 24 and 28, at 27 weeks to 100-500 hz and at 31 weeks responses were observed at 1000-3000 hz. By 3 weeks, the ossicles of the ear, which transmit sound from the air to the cochlea are fully developed, and at birth hearing does not change significantly for most of life.
The issue with discussing music for the unborn is that the term ‘music’ needs a clear definition, as is made clear from ethnomusicological research. Music, according to Western thought, is defined as “the contrast between sound and silence, and a combination between pitch, rhythm, and dynamics”. However, a fetus does not have language or reflective awareness like an adult to perceive music. Music is based strongly on previous musical experience, as we see from cross-cultural music patterns. Therefore, the fetus’ concept of music in human culture can only truly begin at birth.
For the unborn, therefore, there is no concept of differentiating between music and noise, and in fact, there are studies that show that, to the majority of children, there is no clear difference between speech and song until the age of 2! There is, however, clear research that shows fetuses startling dramatically to strong noises from the age of 28 weeks, accompanied by a dramatic rise in heart rate. Early research in this subject by Peiper (1925) claimed that this response is recognized as early as 5 weeks, however; today’s researchers claim this reaction only appears much later. The fetus of 28 weeks also gives an ‘awareness response’, judged by increase in heart rate, to the start of a piece of music.
There have been studies showing a process called ‘naturalization’, or ‘habituation’, which is the exposure of a fetus to a certain continuous noise, and that the fetus will cease to react after a few minutes. This can be distinguished from fatigue by the original response of a quickened heartbeat returning, often accompanied by movements of some kind. According to Pieper (1885) this is the way that we know that the fetus has short term memory.
From these studies, it is clear that the fetus is aware of noise in utero. However, noise alone in most cultures is not a form of music. Continuous pulses, however, is the basis for most types of music, and which we call rhythm. The fetus is constantly exposed to rhythm inside the mother, by exposure to her mother’s heartbeat. When most mothers hold their newborn child, they have a natural tendency to hold their babies on the left side of the chest, near the heart. After analyzing many paintings, books, and photographs, around “80% were found to have the mother with the baby on the left side of her chest.” This preference extends across cultures. The reason that this is interesting is because in the uterus there are many sounds that the baby hears and, once born, is calmed by. Another theory is that there is a similarity between womb sounds and ‘nonsense sounds’, the sounds mothers use to calm their babies. Examples of this are ‘hush’(English) ‘shah’ (Yiddish) ‘Insh’allah (Egyptian) and ‘ushuru’ (Ethiopian) . Perhaps these similarities to womb sounds also explain why there is use of similar sounds in religious practice, such as “Om” used in Buddhist meditation, Tibetan overtone chanting, and Gregorian chants.
Researchers have also found it interesting that across cultures, from the most primitive drumbeats to Beethoven, that all types of music share a startling similarity to the rhythm of the human heart. Adrenaline releases and a quickening heartbeat demonstrate for the fetus the mothers reactions to environmental factors, “preparing the fetus to respond optimally to environmental conditions outside the uterus”
The question now arises, what is the survival value of the fetus hearing before birth? Mammals that hear before birth include ‘people, sheep, goats, and guinea pigs’. Mammals that don’t hear before birth include ferrets, gerbils, rats, and cats.
There are three main theories on why the fetus may be able to hear. The first is preparation for perception. Prenatal sensory learning may provide a foundation for future sensory learning ability. The fetus may be exposed to a limited range of stimuli automatically while in-utero in order to help her acclimate to the diverse range of stimuli she is exposed to after birth.
The second theory is preparation for language. In humans, a child typically understands much earlier than he or she speaks. This could possibly suggest that prenatal exposure to speech speeds up postnatal language acquisition and increases the baby’s chance of survival.
Another theory is that perhaps the sensitivity of the baby to the mother’s emotional state plays a part in postnatal bonding, as the baby is influenced by the mothers ‘facial and vocal expression’, which could possibly explain also why infants are ‘sensitive to emotional implications of pitch contours in both speech and music’. Thanks to this prenatal hearing, babies can recognize their mothers voice, and may recognize and prefer a story heard repeatedly before birth. There is also possibly a preference to the mother’s language versus other languages. These studies show the ability to memorize complex sound patterns and the emotional contours of language, before birth.
Given a choice, babies will change their behavior to activate their mother’s voice rather than another, a piece of music played often during pregnancy, and a story regularly read rather than another. This is another study that indicates memory between the prenatal and postnatal period beyond the womb sounds, and that the baby has capacity for preference and conditioning, as well as suggesting ‘prenatal sound acquisition and discrimination. The skills later involved in learning to speak require that the child perceive components of pitch, tone color, loudness, and duration. When the child experiences a stimulating acoustic environment from as early as several months before birth and during the first years of life, the child has the opportunity to develop “intellectual auditory processing to an optimal level”
Because sound is the most complex prenatally available sense, it is the most researched. After birth, extracting info from other senses increases and the increase in acoustic information is relatively small. The fetus can hear the mother’s voice as loud as she speaksprenatally, and when the mother listens to sounds of average volume, every voice and sound penetrates the womb and isn’t obscured by background sounds. The only times when there is a loss of sound is apparently at extremely high frequencies-where vowels are clear and consonants are not. This perhaps explains a lot when thought of in the context of sounds that babies prefer, as mentioned earlier.
Prenatal response is monitored by non invasive techniques based on compound potentials. Recorders are used measuring the electric potentials from levels of the auditory system. There are two main tools used to measure response. The first is the electroencephalographic (EEG) and the second is the magnetoencephalographic (MEG) method. The EEG monitors responses towards acoustic signals using scalp electrodes, and the MEG uses sensitive magnetic field detectors to measure the auditory responses.
Ultrasound observations are also a valid research tool, and give us a picture of what the fetus is doing in reaction to sound. Sometimes the small movements of a fetus moving its arms, eyelids, or legs are unfelt by the mother, yet with an ultrasound, these responses can be monitored.
Using the EEG, the first fetal reactions towards acoustic stimulation were at 25 weeks. With increasing gestational age, an increasing number of fetal movements combined with fetal heart rate accelerations and reactions can last up to several minutes.
Some factors can influence fetal responsiveness that are beyond researchers control. Gender is one, as female fetuses seem to respond earlier than males to acoustic stimuli, and the other is the behavioral state of the fetus before or during the stimulus.
Some of the claims of the benefits of prenatal stimulation seem to be exaggerated. In Thailand, the cultural belief is that bigger heads are associated with smarter people. Research from Thailand claims prenatal music stimulation results in greater head circumference. This did not prove to be true in western research.
Other research does indicate benefit from prenatal auditory stimulation. Stimulation of the fetus though the use of a sonic belt, (a belt worn by the pregnant mom that plays music), when repeated over a 16 week period showed “advanced levels of conceptualism, balance, space orientation, rhythm, and intuition” in children stimulated this way.
There are many benefits to prenatal stimulation that are shared between the mother and the baby. In the last ten weeks before birth, desire and fantasies for a child increase, and being involved in stimulating development on a mental level can be a great way of promoting bonding. The increased interest by the mother in her pregnancy has many effects for development after birth. It’s not surprising that the benefits for the mother are almost as great as the benefits for the baby, however a mother who does not get any enjoyment from music may find that listening to classical music may have the opposite effect. Generally if the mother is calm and happy, then the developing fetus has much more of a chance of being well adjusted and happy when he arrives.
Other benefits include the possible enhancement of postnatal feeding being enhanced by background music, and that children who had been prenatally stimulated with music were more easily comforted (90%) in comparison with a control group (58%)
In China, children exposed to music stimulation during pregnancy and neonatal periods were monitored and after 5-12 months postpartum, some abilities such as sitting, standing, and walking were observed earlier compared with a control group, and in Venezuela, in a similar experiment, significant improvement was found postnatally in orientation and autonomic stability compared with a control group.
This issue of these milestones appearing earlier in children exposed prenatally to music is not (in my opinion) a coincidence. The cochlea (organ for hearing) and vestibule (organ of balance) are anatomically and physically united, and develop prenatally in parallel. Therefore, the vestibular sense which makes the fetus begin moving at 25 weeks into a cephalic (head down) position before birth may be linked with fetal hearing. Prenatal stimulation through music may affect the early development of the vestibular or balance mechanisms that will help the baby learn to move its body in preparation for walking.
Pilot studies have demonstrated that when only the mother listens to music through headphones, where the fetus would not be hearing the same sounds, fetuses demonstrated a simultaneous reduction of breathing and an increase of movements. It is thus relatively unclear whether the unborn is more affected by the mothers’ emotion during listening or singing than by the pure sound.
While all these benefits are very exciting, some parents place unreasonable expectations on the fetus which may set up lasting negative dynamics between the parents and the children. Parents who feel inadequate about themselves may also try to make up for their own failures such as their perceived lack of musical talent, and should therefore know that success in any field has to do more with hard work than with anything done while in utero.
There are controversial studies which show that exposure to noisy environments such as factories or airfields (now illegal in some countries) can be a cause of birth defects, high frequency hearing loss, or low birth weight. Noise induced stress may also impair the development of the fetal immune system.
No one would place a blaring loudspeaker next to a sleeping baby, and an abdominal loudspeaker on a sonic belt could disrupt the sleep/wake cycles of the fetus , which is vital for brain development. Since the fetus is more often asleep than awake, it is certainly suggested to make sure that the fetus is awake (moving) before performing experiments.
The last concern in exposure to sound stimulation is that there may be issues after birth with bonding. A loudspeaker could confuse a fetus that is very sensitive to his mother’s voice and the sounds that he hears outside the womb, and it seems that through his hearing, he creates a cognitive representation of his mother before birth.
Therefore, since evolution hasn’t prepared fetus to hear sounds louder than their mother, as with a microphone, it would make sense that experiments should be done with the speaker on a very low volume. Research is apparently conclusive that fetuses who are exposed to music are indeed better off than those who are not, but this doesn’t mean that this needs to be done in a lab. The fetus being exposed to his mother’s voice and to music on the level that she hears seems to be a perfect way of stimulating him. Negative connotations could, however cancel out any positive benefits of musical exposure, so if the mother doesn’t want to be exposed, then it’s not worth the effort. Some researchers claim that music with a clear beat is preferable, however it seems that this argument is weak, as the clear beat the baby is exposed to constantly in its mothers heartbeat is all he needs.
The long term effects of prenatal sound stimulation are still unclear beyond these interesting studies. While it is common knowledge that a child needs to hear language of a high standard in order to be able to speak in a similar manner later on, the same holds true for music. The best professional musicians are not necessarily those that had musical parents or who were exposed to music in the womb, but as in anything, are those who are the most motivated to work, work the hardest, and keep at it when the going gets tough. While there are no conclusive studies showing how we can promote these skills in utero, there seem to be many non-musical benefits that the children who were exposed to music in the womb display, and musical exposure seems to be a wonderful way of giving your child a head start in the world.
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