Various embodiments are described herein to reduce sound sensitivities, improve state regulation, and/or reduce auditory processing and social engagement deficits in individuals with such deficiencies by recruiting the anti-masking functions of the middle ear muscles in order to optimize the transfer function of the middle ear for the processing of human speech. In certain embodiments, an individual may be subjected to a training protocol comprising one or more training sessions. During each training session, acoustic stimuli are provided to a subject for a period of time, with or without accompanying visual stimulation. A user response may be determined, for example, before beginning the protocol, during a session, after a session, and/or upon completion of the protocol. Such user response may be employed to adjust the acoustic stimulation, and the adjusted acoustic stimulation may be provided to the subject during a subsequent training session (or at a subsequent time within the same training session). The training protocol may end after a predetermined number of training sessions or upon achieving a desired user response. The training session may be characterized by a fixed protocol during which continuous stimulation is presented for a fixed period of time or by an interactive protocol during which the stimulation presentation is dependent on the reactions of the subject.
