Can London be really conducive to Meditation?

In oversimplified terms (source: Wikipedia), Yoga Nidra is a practice that has become synonymous with yogic relaxation and guided visualisation techniques. It is a way to redistribute the energy in the body and also to connect a conscious resolve to our Unconscious , driving consequently our whole energy towards the realisation of this resolve (Shankalpa).

Part of the practice is to increase our awareness of the sounds around us, going from one to another without trying to understand them. Everyday for a week, practising Yoga Nidra in a remote part of Kanataka, allowed to hear many different birds, insects, the sea in the background, a bell...The refreshing natural surroundings created a pleasant, calming and relaxing experience, conducive to spiritual instruction and meditation.

Back to London, the vibrant voice of the Swami was replaced by a CD, which was bearable. Getting to the part of the Yoga Nidra practice focusing on sounds, there was no natural sounds to be found. The mind was wandering between an overwhelming road drill in the street, car engines accelerating, ambulance sirens, a door banged in the building, more car noises, more sirens, more drilling...

Can we just simply replace the natural sounds by the industrial ones - after all, the awareness of the sound is what matters in the practice, not what triggered them - and just adapt ourselves to our urban environment? Can this really be as conducive to Meditation than a natural surrounding? Most importantly, shall we just accept that, meditation or not, the sound of a bird is no longer a natural thing?