Reducing auditory hypersensitivities in autistic spectrum disorder: preliminary findings evaluating the listening project protocol.

Auditory hypersensitivities are a common feature of autism spectrum disorder (ASD). In the present study, the effectiveness of a novel intervention, the listening project protocol (LPP), was evaluated in two trials conducted with children diagnosed with ASD. LPP was developed to reduce auditory hypersensitivities. LPP is based on a theoretical "neural exercise" model that uses computer altered acoustic stimulation to recruit the neural regulation of middle ear muscles. Features of the intervention stimuli were informed by basic research in speech and hearing sciences that has identified the specific acoustic frequencies necessary to understand speech, which must pass through middle ear structures before being processed by other components of the auditory system. LPP was hypothesized to reduce auditory hypersensitivities by increasing the neural tone to the middle ear muscles to functionally dampen competing sounds in frequencies lower than human speech. The trials demonstrated that LPP, when contrasted to control conditions, selectively reduced auditory hypersensitivities. These findings are consistent with the polyvagal theory, which emphasizes the role of the middle ear muscles in social communication.

Physiological responses to social and physical challenges in children: Quantifying mechanisms supporting social engagement and mobilization behaviors.

Physiological response patterns to laboratory-based social and physical challenges were investigated in 37 typically-developing 3- to 5-year-old children. The study was conducted to determine whether the response profiles during each challenge were similar and whether individual differences in the response profiles to the challenges were correlated. Results demonstrated challenge specific physiological response strategies. In response to the social challenge, respiratory sinus arrhythmia and heart period increased and motor activity decreased. In contrast, in response to the physical challenge, respiratory sinus arrhythmia and heart period decreased and motor activity increased. Neither challenge reliably elicited changes in salivary cortisol. Only heart period responses were correlated between the challenges.