British-based company Masuri has revealed the extra protection, known as a "StemGuard", which is made of foam and a rubber-like material and is attached to the back of a helmet.
Until the death of Hughes, the majority of research and development had focused on protecting the face.
However the new design supposed to better protect the vulnerable areas between the shoulders and the ears.
Hughes died two days after being struck below the helmet while batting in a Sheffield Shield match in November.
"I don't think there was a helmet on the market which would have protected Phillip,” Masuri's managing director Sam Miller told the BBC.
"There had been some talk of protection to that area (the neck) in the past, but it had been a footnote."
The manufacturers claim the new design would not impede a batsman's comfort or ability to move his head.
"This arrangement of the foam and honeycomb gives as much protection as a hard helmet," Miller said.