From the start of development at Orchard Park, it was intended that much of the noise barrier installed along the A14 would be removed.  With the change in land usage and building design along the northern edge of Orchard Park, it has become a contentious issue that the fence should be removed.

As part of the A14 widening project, Costain have published a report covering noise mitigation - 

http://iprojects.costain.com/A14_Public_Area/Public/VOL%201/v1%20-%209%20Noise%20and%20Vibration.pdf

In particular, see p25.