| Course | PS 105 Developmental Psychology |
|---|---|
| Unit | Unit 2 |
| Paper type | Prenatal and infancy paper |
| Length | About 950 words, 6 pages |
| Format | APA 7 student paper |
| School | Herzing University |
| Program | BS in Psychology |
| Updated | October 2026 |
Free sample paper for PS 105 Unit 2
Listening Before Birth: How Hearing the Mother's Voice and Language in the Third Trimester Carries Into Newborn Preferences and First-Year Speech Perception, and Where the Evidence Thins
Student Name
Psychology, Herzing University
PS 105: Developmental Psychology
Instructor Name
March 23, 2026
Listening Before Birth: How Hearing the Mother's Voice and Language in the Third Trimester Carries Into Newborn Preferences and First-Year Speech Perception, and Where the Evidence Thins
The Influence and Its Window
This paper follows one prenatal influence into the first year of life: the sounds of the mother's voice and of the language around her, heard by the fetus before birth. Timing is the organizing idea of prenatal development, and this influence has a clear window. The structures of the inner ear and the pathways that carry sound to the brain develop through the second trimester, and the fetus begins to respond to sound during the third trimester. The sounds that reach the womb are muffled, because tissue and fluid filter out high frequencies, but the rhythm and melody of speech, especially the mother's own voice carried through her body, come through. An influence that depends on hearing therefore operates mainly in the last months of pregnancy, not earlier.
What Is Forming During the Window
The biological groundwork needed here is limited. In the third trimester the auditory system becomes functional and the brain regions that process sound are developing rapidly. What matters for the argument is that the fetus can register repeated sound patterns and that the developing brain may retain something of them. The research below asks whether it does, and what that retained experience looks like after birth.
The Research, Reported With Its Designs
Newborns prefer their mother's voice
DeCasper and Fifer (1980) tested newborns within their first days of life using a nonnutritive nipple connected to a tape player. By changing the timing of their sucking, babies could produce either a recording of their own mother reading or a recording of another woman reading. The newborns adjusted their sucking to hear their mother's voice more often. Because the babies were tested so soon after birth, with very little postnatal exposure, the authors argued that the preference likely reflects listening before birth. The design was an experiment on the newborns' behavior, but the prenatal exposure itself was not controlled; it was simply assumed from the fact of pregnancy.
A passage heard before birth is recognized after it
DeCasper and Spence (1986) went further by controlling what the fetus heard. Pregnant women read a particular children's story aloud twice a day during the last six weeks of pregnancy. After birth, the newborns sucked in a way that produced that familiar story more often than an unfamiliar one, even when both were read by a woman other than their mother. Because the passage was assigned by the researchers, this study comes closer to showing that specific prenatal experience caused a specific newborn preference.
The native language shapes vowel perception at birth
Moon et al. (2013) tested newborns in the United States and Sweden, at roughly a day and a half old, on vowel sounds from English and Swedish. The babies responded differently to vowels from their native language than to foreign vowels, which suggests that some learning of the sounds of the surrounding language had already happened before birth.
Why the Designs Here Are Unusually Strong
Most research on prenatal influences in humans is necessarily observational. Researchers cannot assign pregnant women to drink alcohol, smoke or experience stress, so studies of those influences compare children whose mothers happened to differ and must try to rule out the many other ways those families differ. The research on prenatal listening is unusual because the newborn's response can be tested experimentally within days of birth, and in one case the prenatal exposure itself was assigned. That does not make the studies large or definitive, but it means their conclusions about the first days of life rest on stronger designs than most of the prenatal literature. The weakness lies elsewhere: in the small samples, in the narrow behaviors that can be measured in a newborn, and in the long gap between those first days and the outcomes people most want to know about, such as how well a child will speak or read years later.
Into Infancy
The thread continues after birth. Newborns arrive already attending to the voices and language they heard in the womb, and over the first year their perception narrows further toward their native language. Werker and Tees (1984) found that infants from English-speaking homes could distinguish speech sounds from Hindi and from a First Nations language of British Columbia at six to eight months of age, but by ten to twelve months most could no longer distinguish them, while infants who heard those languages at home kept the ability. The prenatal findings suggest that this tuning to the native language begins earlier than the first year, with the womb as its first setting.
Where the Evidence Becomes Uncertain
The studies are small, often a few dozen babies, and the newborn measures, such as sucking patterns, show preference or discrimination rather than understanding. Beyond the first days, the effects of prenatal listening cannot be separated from everything a baby hears after birth, so claims about later development rest on reasoning rather than evidence. Products marketed to stimulate the fetus with music or lessons go far beyond anything these studies tested.
| Claim | Strength of evidence |
|---|---|
| The fetus hears and responds to sound in the third trimester | Well established |
| Newborns prefer their mother's voice and familiar passages | Supported by small controlled studies |
| Newborns already respond differently to native-language vowels | Supported by one two-country study |
| Prenatal listening shapes language development over later years | Plausible but not directly shown; later effects are mixed with years of postnatal experience |
| Playing music or lessons to the womb improves intelligence | Not supported by this research |
What the Thread Shows
This influence illustrates the course's point that development begins before birth and that timing matters. The fetus does not learn language in the womb, but it appears to learn something about the sound of one voice and one language, and that learning gives newborns a head start in attending to the people and speech around them. The evidence is strongest at birth and fades with time, not because the influence disappears but because, after birth, it merges with the much larger experience of being spoken to every day.
References
DeCasper, A. J., & Fifer, W. P. (1980). Of human bonding: Newborns prefer their mothers' voices. Science, 208(4448), 1174-1176. https://doi.org/10.1126/science.7375928
DeCasper, A. J., & Spence, M. J. (1986). Prenatal maternal speech influences newborns' perception of speech sounds. Infant Behavior and Development, 9(2), 133-150. https://doi.org/10.1016/0163-6383(86)90025-1
Moon, C., Lagercrantz, H., & Kuhl, P. K. (2013). Language experienced in utero affects vowel perception after birth: A two-country study. Acta Paediatrica, 102(2), 156-160. https://doi.org/10.1111/apa.12098
Werker, J. F., & Tees, R. C. (1984). Cross-language speech perception: Evidence for perceptual reorganization during the first year of life. Infant Behavior and Development, 7(1), 49-63. https://doi.org/10.1016/S0163-6383(84)80022-3
PS 105 Unit 2 instructions, in plain terms
Unit 2 of PS 105 asks students to follow one prenatal influence from conception or late pregnancy into the first years and to report what the research does and does not establish. Expect to name the influence and the window in which it operates, describe the biological groundwork only as far as the argument needs, report research with its design attached and mark where the evidence becomes correlational or thin. Much human evidence in this area is observational, and the paper has to say so rather than claim cause. Biology belongs in the paper only to support the psychological thread. Writing about your own pregnancy or baby shares private health information and is best avoided.
Inside the PS 105 Unit 2 example
The paper opens by naming the influence and explaining why its window falls in the third trimester. A short section on what is forming keeps biology to what the argument requires. Three studies are then reported, one per subheading, with designs named: newborn voice preference, recognition of a passage read before birth and native-language vowel perception at birth. A section explains why these designs are stronger than most prenatal research and where their weakness lies. Werker and Tees carry the thread into infancy. A table separates established, supported, plausible and unsupported claims, and the close explains why the evidence is strongest at birth and fades afterward. The thread is followed in order of time, so the reader always knows which window is under discussion.
Reading the PS 105 Unit 2 rubric
The rubric for the prenatal and infancy paper generally rewards a clearly defined influence and window, appropriate biological groundwork, research reported with designs, honest marking of where evidence becomes correlational and a thread carried into infancy, plus APA writing. The window criterion earns credit when timing organizes the paper. Biology scores when it is accurate and limited to what the argument needs. Research reporting is often the largest criterion, rewarding students who name each study's design and what it can establish. Marking the limits of evidence is frequently decisive. Instructors also credit papers that refuse to extend findings to claims the studies never tested.
PS 105 Unit 2 help: mistakes that cost points
Prenatal papers lose points when they survey the whole prenatal period instead of following one influence. Another frequent mistake is stating that an exposure caused an outcome when the evidence is observational. Students often include pages of embryology the argument does not need. Some stop at birth and never reach infancy. Others repeat popular claims, such as music before birth making babies smarter, without checking them against research. Leave personal pregnancy details out entirely. If you need help choosing an influence with a clear window and traceable evidence, one of our writers can build the paper around your choice. A table that grades claims by strength is a simple way to show the reader where evidence stops.
Get a PS 105 Unit 2 example written to your instructions
Attach the Unit 2 instructions and your PS 105 rubric, with the influence or period the assignment specifies and the readings your section uses. We write a custom example that fixes the window first, reports each finding with its design, carries the thread into infancy and closes on what is unknown. First custom sample free, returned in 24 to 48 hours.
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PS 105 Unit 2 questions, answered
How much biology belongs in a psychology paper?
Enough to make the influence intelligible and no more. Your instructions usually indicate the balance, and developmental sections generally want the psychological outcome in the foreground with the biology supporting it. Two or three paragraphs establishing what is forming and when will normally carry a thread; a full account of gestation will crowd out the evidence the rubric is looking for.
Why can I not say an exposure caused an outcome?
Because the studies that would license that wording cannot ethically be run on people. Researchers observe families who differ in exposure and compare outcomes, which leaves other differences between those families as live explanations. Report the association, name the design, mention what the researchers adjusted for, and write the conclusion at the strength the method supports. Markers read that qualification as competence.
Can I write about my own pregnancy or my baby?
Keep it out of the graded file. Prenatal records, delivery notes, a pediatric chart and a child's early history are protected documents, and the child in them never agreed to appear in your coursework. The writing also changes character once it is about your own family, sliding from evidence toward reassurance. A composite case built from published patterns does the same job safely.
Where can I find a free PS 105 Unit 2 sample paper?
This page carries the full PS 105 Unit 2 prenatal and infancy paper free, with the studies, the evidence table and margin notes. Following a different influence? Share the prompt and we trace that influence for you in a free paper, mostly inside 48 hours.
Why can I not say an exposure caused an outcome in PS 105 Unit 2?
Because most human prenatal evidence is observational. The sample explains that only one of its studies assigned the exposure, so only that one comes close to showing cause.