The chants of "Kohli, Kohli". The roar when David Warner was given out on review. The celebrations when Aaron Finch and Steven Smith reached hundreds. The almost collective amazement at Glenn Maxwell's reverse-swept six. The almighty volume when Virat Kohli was dropped by Adam Zampa. The boos when the India supporters thought a Mitchell Starc full toss should have been a no-ball.
The sounds of being at the cricket.
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When the gates opened at the SCG early on Friday afternoon, spectators entered a men's international match for the first time since March 13. A few hours later across the Tasman, they came into Eden Park to watch New Zealand take on West Indies (and what a ridiculous game that turned out to be).
Crowds have been at sport in the two countries since the middle of the year as New Zealand and Australia have, largely, led the way in keeping Covid-19 under control. Crowds have been back at cricket, too, since September when the Australia-New Zealand women's series had spectators in Brisbane which has been followed by fans at domestic cricket.
However, there was a symmetry about Sydney getting there first for men's internationals - if only by a couple of hours, and because of Queensland's U-turn on hosting India - and the volume was something not heard since early this year.
It was at this venue more than eight months ago that the doors were slammed shut on the international game as fans were locked out of the opening ODI between Australia and New Zealand. The ground rattled to the sound of silence (something which has become much more 'normal' since) as everyone got their first experience of social distancing and protocols that would become part of everyday life. The day after, the series was cancelled.
During the intervening months, so much effort has been put in and money spent to keep the show on the road. England managed to get in a full home summer, Pakistan hosted Zimbabwe and in the franchise world, both the CPL and IPL took place behind closed doors. The quality of the cricket has been a testimony to the professionalism and drive of the players, the cut and thrust of the contest helping, in part, to compensate for the empty, soulless stadiums.
But how the big crowds have been missed.
Outside the SCG, hours before play started, the Bharat Army was getting into full swing. The roar when Kohli led India onto the field felt almost deafening - of course, it wasn't but going from zero to thousands of people had that effect.
When India finally broke the opening partnership, successfully reviewing for an edge against Warner, 17,821 sounded like 50,000. Towards the end of Australia's gargantuan innings, a Mexican wave went around the ground. The India supporters enjoyed Starc's opening over costing 20; the Australians lapped up Josh Hazlewood's three wickets. All these things could have happened without a crowd, but they were so much better with one.
Having spectators also added to two poignant moments: the minute's silence for Dean Jones before play started (he will be honoured more extensively during the Boxing Day Test) then at 4.08pm when play paused to remember Phillip Hughes - 408 being his Test cap number - on the sixth anniversary of his death with Finch and Warner taking a moment to glance skywards.
Of course, there was a lot that still wasn't quite normal. Not least the speed of security in getting onto the pitch when protesters against Adani, an Indian company involved in controversial coal mining in Queensland, jogged onto the field. For a moment, nobody moved - players starting to wonder what was happening - before eventually security arrived and escorted the men off while trying to maintain their distance.
On a more day-to-day level, QR codes, temperature checks and reminders to social distance are all part of the new experience. The ground has two zones - controlled and uncontrolled - with the players in the former and no mixing between the two. They are out of quarantine, but for them, the bubble life goes on.
This, everyone hopes, will work for the rest of the summer. It has been confirmed that spectators will be able to attend BBL matches across all the states and it appears Adelaide has escaped the risk of having to have the opening Test behind closed doors after the recent Covid-19 scare in the city.
Melbourne, which endured a 100-day lockdown during a second wave, is set to welcome 25,000 for the Boxing Day Test although there is a push for that to be increased. However, recent comments by Victoria sports minister Martin Pakula cautioned over how far things have already come in a pandemic year.
"I know Cricket Australia and the MCG would like a few more," he told SEN Radio. "What I'd be more inclined to focus on is ... the way I look at it is a month or two ago the idea of the Test going ahead, crowd or no crowd looked so remote, I'm pretty satisfied with the fact we're going to have a Boxing Day Test at 25,000 a day."
Then there are also the reminders of how little it would take to upend the best-laid plans. The events in Adelaide a couple of weeks ago, which led to players being hastily flown out of the state, showed how quickly a situation can change. Across the Tasman, the positive Covid-19 tests among the Pakistan squad and their breaches of the protocol have left the tour on edge.
A warm, sunny Sydney afternoon with chants of "India, India" ringing around the ground, glorious strokeplay, cheers for the runs of Finch, Smith, Dhawan and Pandya, and a high-scoring one-day international was a wonderful, heart-warming experience. But Australia coach Justin Langer summed it up well earlier in the week.
"We've been nervous, we're still nervous, we'll be nervous until the last ball of the summer is bowled. We'll be relieved when we hopefully get through the whole summer."
Today, though, things felt just that little more normal.