Systems, devices and methods are provided for diotically presenting second-order gradient directional hearing aid signals. In one embodiment, the surround visual field is projected on an area partially surrounding or surrounding video content being displayed on a device. The electrical connection may be in the form of a first connector mounted to the first antenna and a second connector mounted to the second antenna. This is achieved by maintaining backpointers to previously processed junction trees during the forward pass and dynamically assembling the Viterbi with each pair of junction trees during the forward pass.