Sensitive Indicators of Childhood Listening Difficulties (SICLiD) Study
Quite a few children with listening difficulties turn out to have clinically normal hearing. These children currently pose a problem for clinical services as it is unclear how they should be treated. Currently, they are sometimes given a series of tests for ‘auditory processing disorder’ (APD). However, the relationship between those tests and the symptoms reported by the children and their families is unclear. Alternately, they may be referred on to other children’s services (e.g. speech/language pathology, developmental psychology), but those services may also be uncertain how to respond. In this study we are assessing listening ability in a sample of children with normal audiograms using a reliable and validated caregiver questionnaire the ECLiPS. The results are related to a series of research tests of the children’s hearing, thinking (cognition), and auditory system biology – ear and brain function. Brain function was studied using MRI. We have found strong evidence from these tests that the children with listening difficulties, but with normal hearing, have impaired forebrain function indicative of impaired cognition rather than impaired hearing.
The ECLiPS caregiver questionnaire (above) allows us to screen for listening difficulties in children. Caregivers indicate whether they strongly agree (SA) to strongly disagree (SD) with 38 statements about their children.
We can visualize connections between active brain areas in children (left) using magnetic resonance imaging (MRI). Here, the connections (red) between speech processing areas (blue) are averaged across more than 40 typically developing children aged 6 -13 years.
Audiological measures in children with listening difficulties
In the Listening lab, Dr. Hunter is collaborating to uncover hearing issues that may relate to children’s listening problems. She uses sensitive tests that have been developed in her previous collaborations with Dr. Doug Keefe at Boys Town National Research Hospital in Omaha, NE and Dr. Pat Feeney at the National Center for Rehabilitative Audiologic Research in Portland, OR. These tests are capable of detecting very high frequency changes in hearing sensitivity, problems in the function of the eardrum and middle ear, and in the inner ear. In the SICLiD study, she recently published results showing overall that children with listening difficulties do not have problems in these areas that could explain their difficulty in understanding. However, some children had poorer high frequency hearing sensitivity, poorer inner ear and middle ear function that were clearly related to previous history of otitis media treated with eardrum tubes. Dr. Hunter is also collaborating on the OtiS study to study children who could benefit from the new hearing aids due to problems they have understanding speech in noise.
Speech envelope tracking in children with listening difficulties
As stated previously, there are many children with listening difficulties (LiD) who have clinically normal hearing. A primary concern of parents of children with LiD is their difficulty listening in class. A critical cue of selective attention to speech is the low-frequency (<10 Hz) fluctuation of speech amplitude, the so-called speech envelope. We hypothesize that children with LiD may have difficulty processing speech envelope in their brains. We are going to assess the brain’s response to speech envelope in children with LiD using magnetoencephalography (MEG).
Autism Spectrum Disorder and Auditory Processing Disorder in Children (ASD) Study
Autism is characterized by difficulties with social skills, repetitive behaviors, speech and nonverbal communication. It affects about 1 in 50 or 2% of children in the United States. Although understanding autism is progressing rapidly, it is unclear what role hearing and listening plays in the disorder. Hearing problems have often been reported, but have rarely been tested carefully. We are studying the function of the ear and the brain in children with high functioning ASD; these are children with more mild forms of autism spectrum disorder (ASD). We use the same sensitized measures of hearing function and MRI as we are using in our studies of childhood listening difficulties, described in the SICLiD study. The MRI research will identify connectivity patterns between speech and other brain cortical regions. Together, these approaches will pinpoint mechanisms of listening abilities and disabilities in children with ASD, enabling translation into evidence-based clinical tests and targeted treatments.
A listening test called ‘Listening in Spatialized Noise – Sentences’ (LiSN-S) was developed by Sharon Cameron and Harvey Dillon in Australia. It tests the ability to listen to a talker (T) speak sentences in the presence of two competing distractor voices (D1, D2). As shown above, the distractors can be in the same or different positions, and have the same or a different voice. The LiSN-S thus varies the task difficulty in a realistic way, challenging all listeners in our studies.
Digits-In-Noise (DIN) Study
The digits-in-noise (DIN) test is an automated, self-administered hearing screening tool for detection of hearing loss. This project aims to increase sensitivity of the DIN test to different types and degrees of hearing loss using interaural antiphasic digit presentation and low-pass filtering of the noise at higher frequencies. The low-pass filtered DIN test has also the potential to be used for detecting early signs of hearing loss known as extended high frequency hearing loss, impaired detection of sound above the 8 kHz limit of current audiological testing. This could in turn lead to timely and effective prevention and intervention approaches. In collaboration with the hearX company, we aim to develop the smartphone version of this test that would be a powerful tool for population-based screening. We believe the enhanced functionality combined with smartphone delivery could make the DIN test suitable as a primary hearing screen that is accessible to a large global audience.
The Oticon (OtiS) Study
The Oticon Study, or more fondly referred to as the OtiS study, investigates behavioral and cortical plasticity from wearing hearing aids with noise reduction systems. In 2018 we completed a pilot study in children aged 6-12 years with mild to moderate hearing loss. The children's caregivers reported a significant improvement in their child’s everyday hearing. However, we did not find behavioral changes in their language, cognition or academic abilities. We used the results from this pilot to power our main study.
The figure above depicts the stimuli presentation for the Boystown speech reception task used in the OtiS Study. In the three conditions shown, the participant is seated in a sound ring of speakers and asked to repeat the target words (presented at either 0° or -60°) while speech-shaped mask noise is presented in the two speakers behind (at 135° and -135°).
We are currently analyzing the results from our main study - a double-blind clinical trial (view here at clinical trials.gov) comparing adaptation to OpenSound Navigator and Omni-directional hearing aids over eight months of use. We are using outcome measures of language, cognition and academic ability along with caregiver reports and magnetic resonance imaging (MRI).
This study is funded by Oticon and the Oticon Foundation.
Reference: Pinkl, J., Cash, E., Hunter, L. L., Ferguson, S., Evans, T., Nejmen, T., Hamilton, J., Moore, D. R. & Stewart, H. J. (Under review, American Journal of Audiology). Short-term pediatric acclimatization to adaptive hearing aid technology. medRxiv.
Gaming and Hearing Study
This project covers studies exploring how computer games can be used in our research.
Action Video Game Players
In collaboration with C. Shawn Green, University of Wisconsin-Madison, we assessed action video game players’ auditory cognition and perception, specifically their speech-in-noise abilities. It has been shown extensively that gamers who play first- and third-person shooters have superior visual cognition and perception abilities. We found that this effect did not cross into the auditory domain. However, the way our participants interact with audio in computer games differed greatly from how they interact with the visual elements. The majority of our participants listened to other audio sources during gaming (e.g., podcasts, tv, group-chat). The few that did listen to their games’ sounds did not use surround sound technology.
Reference: Stewart, H. J., Martinez, J., Perdew, A., Green, C. S., & Moore, D. R. (2020) Auditory cognition and perception of action video game players. Scientific Reports, 10(1), 1-11.
We are developing a virtual reality speech-in-noise assessment for children. This project is currently in the software development stage with Game Theory co. (https://www.gametheoryco.com/vr-hearing). We will be comparing how children perform in a normal testing environment to virtual reality with the Oculus Rift and Go headsets.
This study is funded by Action on Hearing Loss and National Science Foundation: Engaging Learning Network.