Baby's Auditory Perception: What Do Babies Hear? When does a fetus have auditory perception?

While still in the womb, months before birth, the fetus can already hear and may recognize his mother's voice and other sounds.

However, adults are much more sensitive to sound than newborns.

Over the first year of life, there is significant improvement in sensitivity to sounds, especially high-pitched sounds.

We know that a newborn baby can hear because we can observe his reactions to sound, which can include changes in heart rate and breathing, becoming quiet, turning his eyes or head towards the sound, or tightening his eyelids.

The habituation technique is used to see which sounds the babies can differentiate, by getting them used to a certain sound and then introducing them to a different sound and seeing if they react differently to the change in stimulus.

Small babies can differentiate between the duration, frequency and intensity/loudness of sounds that they hear.

Infants are particularly attuned to the parts of sounds that will be crucial for perception of speech later on.

Over the first one and a half years of life, the child's ability to localize sounds becomes keener.

This trait was present at birth to a certain extent, then diminished partially, and became stronger and better at around four months.

The newborn looks toward sounds and has auditory capabilities, which are sharpened as he experiences, grows and explores his environment.

Studies of exploratory inter-modal perception show that babies have a grasp of auditory-visual relations at birth.

Researchers have explored the tendency of babies to appreciate and pay attention to visual events that correlate with the sounds that they hear.

They seem to recognize the correspondence between the sounds and the sights in their environment.

This was seen when they followed the lips of the correct person speaking, or other movements that matched a particular sound.

At the age of four months, they could already use their knowledge of different items' hardness and properties, together with their auditory abilities, to know what sounds to expect from certain objects when banged together, based on integrating different senses together.

At this time, they could also differentiate between the voice of an adult and child, male and female, mother and father, or mother and female stranger.

In all these instances, they correctly matched and looked towards the person whose voice they heard.

Infants differentiate and prefer lullabies over adult songs, even if they are foreign.

They are particularly aware of parts of sound that are crucial for later language perception, such as human voice frequencies, speech sounds and location.

Clearly, the hearing abilities mentioned above prepare the infants for social interaction and the acquisition of speech later on in life.