Journal of Phonetics & Audiology
Open Access

Do Babies Distinguish between Sounds and Noises?

Shelly Toscano^{* *}Correspondence: Shelly Toscano, Department of Otorhinolaryngology, University of Copenhagen, Copenhagen, Denmark, Email:

Author info »

Description

The world appears to sound vastly different to babies than it does to adults. Sometimes the world filled with a cacophony of sounds, making it difficult for babies to identify a single sound from the rest of the noise. This is because babies are generalists who hear all frequencies simultaneously so they may respond to unexpected sounds.

Babies have a new way of hearing to the world. In actual life, we are exposed to a wide range of noises. The adult brain somehow separates all of the sounds we hear into their sources and then concentrates on the one we want to hear. Adults hear in a restricted band of sound; however babies appear to hear in a different way. They don't pay attention as selectively as adults and don't pay attention all of the time. Instead, they appear to always be listening in broadband or to all frequencies at the same time. For a long time, researchers have known that babies are born with working hearing and that their sensitivity to sound improves substantially over childhood. The average child's hearing improves until the age of ten, when it is comparable to that of an adult.

Researchers evaluated 73 babies aged 7 to 9 months and 40 adults aged 18 to 30 years to learn more about how babies hear. Everyone's hearing was normal. They were each given four halfsecond bursts of a 1000-hertz tone created by a computer and a 1000-hertz wideband noise that sounded like telephone dial tone or static. The tone or noise was sometimes played alone, and other times the sounds were masked with background noise. The sounds were played at various decibel levels to check if the participants could detect them. Subjects listened to the sounds through foam earphone inserts in their right ear canals.

The four different sorts of sounds were generated at random by the computer, and the babies were taught to respond when they heard them. Here, baby sat in their mother's lap in a test booth, while an assistant kept the baby attentive by manipulating silent toys on a table in front of them. To ensure that the assistant and mother could not hear any of the noises delivered to the baby, they wore headphones and listened to masking sounds. Through a window or a video monitor, an observer outside the booth monitored and scored the baby’s responses. The activation of a mechanical toy was used to reward a baby for responding to a signal. When baby heard something, they usually turned toward it or adjusted their activity level. Baby may also respond by altering their facial expression or staring at their mother. Adults were assessed in the same way, sitting in the booth alone. When they heard a sound that activated the mechanical toy, they were instructed to raise their hand.

Conclusion

Eventually, researchers observed that babies are better at identifying noise than tones on average. The difference in noise detection between babies and adults was 14 decibels in the quiet condition versus 7 decibels in the masked trials. Adults with a 15-decibel deficit have a slight hearing loss, according to researchers. With the background masking, the difference in identifying the tone between babies and adults was 10 decibels for the tone and 5 decibels for the noise.

Considering the present western culture, however, a baby has a significant disadvantage. The amount of noise we expose makes it difficult for babies to listen. The practical example is the background noise can be a concern while chatting to a baby or reading her a tale. So, turn off the television or the radio while making a conversation or reading her a tale.