Effectiveness of Noise-Attenuating Headphones in Children with Autism Spectrum Disorders
Objectives: The objective of this study was to examine the effectiveness of two types of NAH in reducing stress in children with ASD while in natural environments.
Methods: Single-case study design with randomization to sequence of intervention (ABAC or ACAB) was used to test the effectiveness of two NAH. Six children between the ages of 8 and 16 diagnosed with ASD completed the study and were randomly assigned into two groups for different phase sequences. Five points of data were collected in the 4 phases of baseline, intervention 1, wash out, and intervention 2. Participants were provided with a set of Bose over-ear and in-ear NAH for the intervention phases. Physiological data of heart rate and electrodermal responses (EDR) were collected using an Empatica wireless wearable device to measure arousal state. Momentary assessment data was collected on type of daily activity and environmental stimuli. Smart phone technologies collected decibel readings two times in each session and a visual scan of the environment. Moeyaert’s model parametrization, a multilevel hierarchical linear random effect model was used to evaluate treatment effects (Manolov & Moeyaert, 2017).
Results: Participants had significantly lower NS-SCR scores (G1: = 15.67, p < .001; G2: = 33.65, p < .001) during the intervention phases as compared with the baseline. The levels of NS-SCR scores did not differ (G1: = 0.35, p = .557; G2: = 2.07, p = .151) between over-ear and in-ear phases. SCL scores were also significantly lower (G2: = 238.04, p < .001) during the intervention phases compared with the baseline for a random subsample. SCL scores were similar (G1: = 0.00, p = .979; G2: = 0.04, p = .845) between different intervention phases. Participants also had lower heart rates (G1: = 23.87, p < .001; G2: =111.23, p < .001) during intervention phases as compared with the baseline, in particular during the in-ear intervention (G1: = 23.66, p < .001; G2: = 43.29, p < .001). Further analyses showed that the interventions may have moderating effects on the relationships between environmental noises and the physiological responses, in particular NS-SCR ( = 3.34, p = 0.067) and SCL ( = 2.83, p = 0.092) levels.
Conclusions: Results provide preliminary evidence for the use of NAH to reduce or maintain physiological arousal levels in stimulating environments for children with ASD. Generalization is limited due the single-case approach. Findings provide information to guide treatment planning when integrating environmental-based interventions in natural settings.