 Hello everyone. My name is Lina Mutlaksada. I'm a research associate at Cincinnati Children's Hospital. My talk is about the role of a specialist from masking, in predicting listening difficulty in children with central artery processing disorders. So artery processing disorder indicates difficulty processing sounds in the central artery nervous system. APD may be diagnosed to reported listening difficulty with reduced behavioral and cognitive function, but normal hearing, normal conventional audiogram. There is a legal agreement as to what qualifies as APD and LID, how they differ and which tests are appropriate for diagnosis and management. Recent work suggests that LID or APD is preliminarily dependent on cognitive, including listening problems. However, there is also evidence that a deficit in a spatial hearing and difficulty understanding the speech and noise may indicate a disorder of the central artery system. So this study aimed to isolate cognition from auditory contribution to spatial release from masking, which is one of the auditory abilities essential for auditory scene analysis and speech perception in noisy, multi-hoccer environments. So in this study we had 17 children with listening difficulty defined by either professional diagnosis of APD or parent's report of listening difficulty. We also had 18 typically developing children as a control group. Participants were 8 to 17 years old and mean age was 11.4 years old, 63% of them were male. We did standard and extended high frequency audiometry. As you can see, both groups had normal hearing at a standard frequency range and only few of them had extended high frequency hearing loss. We also compared speech reception thresholds on two tasks. A special advantage measure of the listeners, which is speech sentencing noise test, listeners had four conditions. For the purpose of this presentation, we only talk about these two conditions, a co-located condition known as low-queue both target and maskers are presented from front speakers, also known as a head condition, talker and target and masker coming from zero azimus. And then we have a spatial advantage condition in which target is spatially separated from the masker. Maskers are located at plus and minus 90 azimus. For the sound field digital noise test, we have similar condition, a head condition in which both digits and multi-talker bubble coming from front speaker and then side condition or spatially separated condition that maskers are spatially separated from target. They are presented at minus and plus 90 degrees azimus. So as you probably know, sound field digital noise or digital noise test is much easier or cognitively less demanding compared to listeners, which has a sentence in noise test. So for digital noise, we have sequence of three digits, zero to nine presented against multi-talker bubble noise. And digits, sequence of three digits and presented in random order make the test a lot easier than listeners, low-queue and spatial advantage tasks. So here we have results. Both LID and TD groups had better speech reception thresholds on both tasks when the noise was spatially separated. So this is showing sound field digital noise speech reception threshold. As you can see, 90 condition had a lot better speech reception threshold. More negative means better hearing than a head condition. And then here when we go from low-queue to spatial advantage from a co-located condition to a spatially separated condition, the CS scores drastically improve. Despite similar performance at co-located condition in sound field digital noise test, LID children had significantly poorer speech reception threshold than TD children at spatially separated condition, at 90 condition. And this results in significantly poorer spatial release from masking for the digital noise test. However, SRM or condition in listeners task or spatial advantage measure of listeners was not significantly different between the two groups, LID and TD groups. So overall, this is showing that children with LID had significantly poorer ability to differentiate target from background noise when the task was less demanding, was much easier. So digital noise test compared to the listeners. It's worth mentioning that there was significant correlation between sound field digital noise SRM and listeners spatial advantage. So this task was significantly correlated. However, listeners spatial advantage was not significantly, the score was not significantly different across groups. So to wrap up, as I just mentioned, sound field digital noise was more sensitive to LID than listeners. So the task was less cognitively demanding and I was measuring the ability like bottom up auditory perception. And a related difference in SRM between LID and TD groups on both tasks provides a long sound evidence that brain mechanisms prelimarily serving bottom up auditory perception may contribute to listening difficulties in children with APD. So thanks for listening. I'm happy to answer your questions.