Pilot Study of Assistive Listening Devices in Treating Auditory Processing Deficits in Neurofibromatosis Type 1

NF1 is a common genetic condition with a prevalence rate of at least 1 in 2,700 live births. While not diagnostic of the condition, cognitive and behavioural impairments are the most commonly cited childhood complications of NF1. NF1 is also highly comorbid with ADHD (40%) and autism spectrum disorders (ASD; 25%). Auditory Processing Disorder (APD) is characterised by abnormal auditory nerve function in the presence of normal functioning cochlear sensory hair cells. Common impairments include a reduced ability to perceive rapid changes in auditory signals (e.g., brief gaps or amplitude fluctuations) and speech perception difficulties in the presence of background noise, even at signal to noise ratios that would be expected in everyday listening environments (e.g., classrooms; playgrounds). Our recent phenotyping study of 36 NF1 individuals indicated that a significant proportion presented with convincing evidence of APD, compared to age matched healthy control participants. The children in our study who demonstrated clinically impaired performances on two or more tests of auditory processing, on average, also scored within the clinical range on parental questionnaires of inattentive ADHD symptoms. The clinical question that remains is whether auditory processing deficits in NF1 children can be treated. Intervention research suggests that assistive listening devices (ALD) attenuate speech processing deficits associated with APD in the general population. While there is evidence that ALD can improve listening and educational outcomes in other hearing-impaired populations, these systems have not yet been explored as an intervention option for children with NF1. The current clinical trial is a pilot study assessing all elements of the study design (recruitment strategy, tolerability of the study product, study duration, study procedures and outcome measures) to assess whether ALDs are acceptable and feasible for the conduct of a full-scale randomized clinical trial to treat auditory processing deficits in NF1 children. Eligible participants will have their hearing assessed under two conditions (with and without ALD) and testing order will be randomised. They will then be randomised to one of two treatment sequences: 1) being fitted with an inactive ALD for two weeks, followed by active ALD use for two weeks or 2) being fitted with an activated ALD for two weeks, followed by a period of two weeks of use with an inactivated ALD. We hypothesise that children will exhibit improved hearing outcomes while wearing the active ALD, as measured by an objective audiology assessment, and by questionnaire ratings from children, their parents and teachers.