How a mother’s voice shapes her baby’s developing brain

It is no surprise that a child prefers its mother’s voice to those of strangers.  Beginning in the womb, a fetus’s developing auditory pathways sense the sounds and vibrations of its mother.  Soon after birth, a child can identify its mother’s voice and will work to hear her voice better over unfamiliar female voices.  A 2014 study of preterm infants showed that playing a recording of the mother’s voice when babies sucked on a pacifier was enough to improve development of oral feeding skills and shorten their hospital stay.  A mother’s voice can soothe a child in stressful situations, reducing levels of cortisol, the stress hormone, and increasing levels of oxytocin, the social bonding hormone.  Scientists have even traced the power of a mother’s voice to infants’ brains: a mother’s voice activates the anterior prefrontal cortex and the left posterior temporal region more strongly than an unfamiliar voice, priming the infant for the specialized task of speech processing.

While it makes intuitive sense that a mother’s voice has special power over infants and toddlers, what happens as children grow up?  Continue reading

How does the brain locate sound sources?

The brain has an amazing ability to identify the source of sounds around you. When driving, you can tell where an approaching fire truck is coming from and pull over accordingly. In the classic swimming pool game of “Marco Polo,” the player who is “it” swims toward the players who says “Polo.” In the field of neuroscience, this ability is called sound localization. Humans can locate the source of a sound with extreme precision (within 2 degrees of space)! This remarkable feat is accomplished by the brain’s ability to interpret the information from both ears. So how does your brain do it?Continue reading

The Auditory System: From Sound Waves to Brain Waves

Our human experience is enriched by our senses. The world would appear to be a dull place if the brain did not endow us with the ability to construct visual images, appreciate the complexity of a song, experience the touch of a loved one, and perceive the smells and tastes of our favorite foods. Each of these sensory modalities (vision, hearing, touch, smell, and taste) is incredibly complex, requiring specialized structures working in sync with interconnected network of neural circuits. Together, they allow for a rich experience of the world.Continue reading

Hearing is Believing: Cells that Enable Hearing after Birth

The sense of hearing is a critical part of how we experience life and the world around us. It is so important, in fact, that the ears are fully formed and functional when we are born. Despite its significance, hearing is often underappreciated until it is lost. Hearing loss affects more than 10% of all people worldwide. Whether it is due to age, exposure to loud noises, or genetic mutations, hearing loss occurs when hair cells, the receptors in the ears that respond to sound, become damaged and die. One of the biggest challenges in counteracting hearing loss is that hair cells cannot repair or regenerate themselves, so the damage is often permanent.Continue reading