Subway Noise and the Haifa Carmelit

While I interested in reducing the noise levels in the Carmelit, which has switched from rubber-tired vehicles, in a manner somewhat like the Monreal and Paris Metros (although the Carmelit is an underground funicular, without tra;iction motors on its two counterbalanced trains), I though I would look at the problem in a more general light. What is your opinion of the dimensions proposed for a sample case as follows:

A is upper side-wall, B, lower side-wall, C. In trackbed

B is in use in Toronto if memory is correct. For clearance and other reasons, I’ve asked for C for the Carmelit.

Steve Sattler’s photo:

The proposed sound-sbsorbing treatment locations: