Can a Baby Hear Before Birth? The Talmud’s Answer

The prohibition against eating and drinking on Yom Kippur is widely known throughout the Jewish world. Yet Jewish law also makes it clear that when fasting poses a risk to life, eating is not only permitted, but it becomes an obligation.

The Mishnah (Yoma 8:5) teaches that if there is a danger to life caused by fasting, the prohibition is set aside. One of the examples mentioned is the case of a pregnant woman who smells food and feels an intense craving: “A pregnant woman who smells food — she is given food until she recovers.”

Rashi explains the reasoning behind this law: “The fetus smells the aroma of the food and desires it. If she does not eat, both of them are in danger.”

According to this explanation, when a pregnant woman suddenly experiences a powerful craving after smelling food, the desire may not originate with her alone. Rather, the fetus senses the smell through her and longs for it. If she refuses to eat, both the mother and the unborn child could face danger. In such cases, preserving life overrides the fast of Yom Kippur.

A Remarkable Story in the Talmud

The Talmud (Yoma 82b) records two striking stories illustrating this principle.

In the first case, a pregnant woman smelled food on Yom Kippur and developed a powerful urge to eat. The people present consulted Rabbi Yehuda HaNasi about how to proceed.

He advised them to whisper in the woman’s ear that it was Yom Kippur, hoping that this reminder might calm her craving. When they did so, the fetus stopped craving the food and the woman became calm.

Rabbi Yehuda HaNasi then quoted the verse: “Before I formed you in the womb, I knew you.” According to the tradition, that unborn child later grew up to become the great sage Rabbi Yochanan.

The Talmud recounts a second case with a different outcome. Another pregnant woman smelled food on Yom Kippur and could not control her craving. The people asked Rabbi Chanina what should be done.

He instructed them to whisper to her that it was Yom Kippur. This time, however, the craving did not subside, and the woman had to be fed.

Rabbi Chanina then cited the verse: “The wicked are estranged from the womb.”

The child born from that pregnancy later became Shabtai, a merchant known for hoarding fruit in order to manipulate prices.

How Earlier Scientists Might Have Responded

For centuries, rational thinkers might have reacted to these passages in the Talmud with skepticism.

From a purely material perspective, the fetus in the womb was often viewed as little more than developing tissue, lacking the abilities of a person who has already been born. The idea that an unborn child could sense smells, respond to external stimuli, or even hear words spoken to the mother might have seemed implausible.

How could a fetus perceive what is happening outside the womb? How could it feel desire? And how could it possibly react to a whisper spoken in its mother’s ear?

Such questions would likely have been raised by many scholars in earlier centuries.

What Modern Science Has Discovered

In recent decades, however, scientific research has dramatically expanded our understanding of fetal development.

With the help of ultrasound imaging, monitoring devices, and advanced recording technologies, scientists have observed that the fetus is far more responsive to external stimuli than once believed.

Research shows that by around twenty-four weeks of pregnancy, the fetus demonstrates remarkable neurological development. Its eyes move rapidly during sleep, in patterns similar to those seen in children and adults during dreaming.

Studies indicate that fetuses hear sounds from outside the womb. They often respond to music and may move rhythmically, as if reacting to sound patterns.

Even more striking, newborn babies show evidence of memory formed before birth. They tend to recognize and prefer familiar sounds such as their mother’s heartbeat, their mother’s voice, and even stories that were read aloud during pregnancy. Some infants are also able to recognize music that their mothers frequently listened to while pregnant.

These findings suggest that birth is not the beginning of awareness, but rather the continuation of a complex developmental process that began much earlier.

The Perspective of Jewish Tradition

Despite these discoveries, science still cannot fully explain how a fetus perceives external sensations such as smell or sound.

From the perspective of Jewish belief, however, the Torah — given by the Creator of the world, contains the essential knowledge needed for the observance of its commandments. The teaching that a fetus can sense a smell and develop a craving reflects this understanding.

Therefore, if a pregnant woman smells food on Yom Kippur and cannot calm herself, she must be fed, because the safety of both mother and child takes precedence over the fast.

The sages also concluded from these teachings that the fetus is capable of hearing and responding to sounds. When a whisper to the mother can calm the unborn child, it suggests that the fetus not only hears but reacts to what it perceives.

A Midrash About Yaakov and Esav

This concept appears again in a famous Midrash about Rivka’s pregnancy with Yaakov and Esav.

The Torah describes her experience with the words: “The children struggled within her.”

According to the Midrash, whenever Rivka passed by synagogues or houses of study, Yaakov would struggle to emerge, while whenever she passed places of idol worship, Esav would struggle.

From this tradition, the sages derived several insights:

• The fetus possesses a way of sensing its surroundings.

• Repeated fetal movements near certain environments may reflect inner tendencies.

• The unborn child is capable of hearing external sounds.

Modern science has already confirmed the ability of the fetus to hear sounds from the outside world.

For believers, this convergence between ancient teachings and modern discoveries offers a fascinating reminder that insights preserved in the Torah and rabbinic tradition often anticipate truths that science gradually uncovers over time.