Research Shows 6-Month-Olds' Ability to Understand Speech Improves When They Hear Less Distortion
A new study from a UT Dallas researcher demonstrates the importance of considering developmental differences when creating programs for cochlear implants in infants.
“This is the first study to show that infants process degraded speech that simulates a cochlear implant differently than older children and adults, which begs for new signal processing strategies to optimize the sound delivered to the cochlear implant for these young infants,” Warner-Czyz said.
Cochlear implants, which are surgically placed in the inner ear, provide the ability to hear for some people with severe to profound hearing loss. Because of technological and biological limitations, people with cochlear implants hear differently than those with normal hearing.
Think of a piano, which typically has 88 keys with each representing a note. The technology in a cochlear implant can’t play every key, but instead breaks them into groups, or channels. For example, a cochlear implant with 22 channels would put four notes into each group. If any keys within a group are played, all four notes are activated. Although the general frequency can be heard, the fine detail of the individual notes is lost.
Two of the major components necessary for understanding speech are the rhythm and the frequencies of the sound. Timing remains fairly accurate in cochlear implants, but some frequencies disappear as they are grouped.
More than eight or nine channels do not necessarily improve the hearing of speech in adults. This study is one of the first to examine how this signal degradation affects hearing speech in infants.
Infants pay greater attention to new sounds, so researchers compared how long a group of 6-month-olds focused on a speech sound they were familiarized with —“tea”’ — to a new speech sound, “ta.”
The infants spent more time paying attention to “ta,” demonstrating they could hear the difference between the two. Researchers repeated the experiment with speech sounds that were altered to sound as if they had been processed by a 16- or 32-channel cochlear implant.
The infants responded to the sounds that imitated a 32-channel implant the same as when they heard the normal sounds. But the infants did not show a difference with the sounds that imitated a 16-channel implant.
“These results suggest that 6-month-old infants need less distortion and more frequency information than older children and adults to discriminate speech,” Warner-Czyz said. “Infants are not just little versions of children or adults. They do not have the experience with listening or language to fill in the gaps, so they need more complete speech information to maximize their communication outcomes.”
Clinicians need to consider these developmental differences when working with very young cochlear implant recipients, Warner-Czyz said.
Other authors of the study include Dr. Derek Houston from Indiana University School of Medicine and Dr. Linda Hynan from UT Southwestern Medical Center.
This work was supported by a grant from the National Center for Advancing Translational Sciences.
Ben Porter | Eurek Alert!
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...
Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.
A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
21.04.2017 | Physics and Astronomy
21.04.2017 | Health and Medicine
21.04.2017 | Physics and Astronomy