Could be winter jasmine (jasminum nudiflorum) although that's more of a climber or wall shrub. It has bare, green stems.
Could it be Forsythia flowering early or mahonia....holly like evergreen leaves with small spikes of yellow flowers coming from a central rosette.
Lot's of winter flowering plants, many of them are sweetly scented too.....for a gorgeous scent, try sarcocca (called christmas box).....tiny little flowers on an evergreen shrub which are devine.
Any better description of the hedge would be useful