• There is a wide range of materials available for acoustic management of buildings and structures - go check out some architectural acoustic companies for examples.  The 'best' materials are often semi-rigid foams, possibly with a high-inertia component to attenuate low frequencies. 'Soundproof' rooms use foam cones or pyramids, because the shape of the material also matters a great deal.  With specially-designed forms, sound can be trapped in a multiply-scattering crevice, greatly increasing the absorption and reducing reflection.  Note that for auditoriums, one does not want zero reflections.

massive walls and space between it and any neighbouring building

Dear Mr. J. R. Potter, thanks a lot for your valuable information, I would like to find that material, so thank you Mr. Stephen Fargo for your suggestion, how do you think if the used wall is thin. and not massive 

Hi Hidjan

Practically impossible.   if the material is a panel applied to a sub frame, acoustical connections.  

Also, as a lightweight material, Hebelstone (air entrained concrete blocks) is said to have reasonably good acoustical properties.

but basically in my experience as an architect, it is a lost cause

Mr Fargo, your experience is important for my next step in studying acoustic absorber, many thanks for your description  

Hi Hidjan

If a porous Absorber is your favorite absorption technology, you can take a look for "basotect" its a high performance Absorber from BASF

If you emphasize waterproofness and fire resistance I would recommend some kind of Helmholtz resonators, preferably perforated panes. It could be realized from some kind of metal or concrete or epoxide composited sand.

Mr. Henneberger, I am interested to know more about basotect, it is strange material to me, thanks for your information, and for Mr. Jiricek, I want to develope noise absorber for absorbing high frequency noise not low frequency,  to my. my mind Helmholtz resonator is for low frequency noises, thank you 

Could you specify your frequency range? Resonators are tunable so even if it is not usual it can be used for any frequency, but if you exceed say about 5 kHz it is not feasible.

Mr Jiricek, would you inform us completely about the resonator that can be used for absorbing noise at the frequency range between 1000 - 4000 Hz, thanks!

Mr Jiricek, Take a look at. http://www.vicoustic.com/. You will first need to determine the frequencies you wish to combat. 

http://www.vicoustic.com/

Thank you Mr. Alessandro Ruggiero for your valuable information