It was the ripple of respectful applause as King Abdullah of Jordan and His Royal Highness Prince Salman bin Hamad Al Khalifa, Crown Prince and Deputy Supreme Commander, entered a packed conference hall at the beginning of the seventh Manama Dialogue.
And what does it look like? The watchful expressions on the faces of Ms Clinton's entourage as the US Secretary of State swept into the hotel. The stream of dignitaries that flowed into the ballroom in front of the VIPs as they took their places for the opening address.
The Manama Dialogue, organised by the International Institute for Strategic Studies (IISS), is an annual gathering of the great and the good - who come to our city once a year to talk about security in the Middle East.
It's probably the largest assembly of government ministers, generals and security analysts you are likely to see in the Middle East at any time in a given year.
The three dominant themes that emerged from the Dialogue were the problems of Yemen, the deadlock in Palestine and, of course, the nuclear ambitions of Iran.
On Yemen, there was consensus that inward investment is as important as counter-insurgency support, while the standout message on Palestine came from an eloquent address by King Abdullah of Jordan. His view that time is running out for a two-state solution was widely endorsed by conference delegates.
As for Iran, the hand of friendship offered by Ms Clinton seemed to fall on stony ground. Iranian Foreign Minister Manouchehr Mottaki maintained the government line in denying that Iran wishes to develop nuclear weapons and blaming most of the tensions in the region on foreign interference.
However, analysts I spoke to did detect a slightly softer tone than they were used to hearing from Iranian leaders. Cause for hope, perhaps?
But at any conference that brings together such a gathering of movers and shakers, it's in private discussions where the real business is done - outcomes we may never know about; discussions by unlikely partners; enhanced understanding of respective positions; sharing of information...
Except this time I'd put money on none of that information reaching Julian Assange and his colleagues at WikiLeaks. After all, this was a security conference.