This is the new recorded announcement that the iBus system is making on all London buses, advising passengers to hold on while the bus is moving. There's been a lot of discussion of this in the national and London media, with some people finding it irritating that the same warning is issued when leaving every bus stop. Back in the days of bus conductors, some of those men and women would say something like 'Hold very tight, please' as they pressed the bell twice to tell the driver to start off.

Mastering Azure Service Bus

What Is A Service Bus Architecture

Connect Your Services with Microsoft Azure Service Bus