In the U.S. Senate, this is what nothing sounds like.

“Mr. Akaka.”

At 9:36 a.m. on Thursday, a clerk with a practiced monotone read aloud the name of Sen. Daniel K. Akaka (D-Hawaii). The chamber was nearly deserted. The senator wasn’t there. Not that she was really looking for him.

Instead, the clerk was beginning one of the Capitol’s most arcane rituals: the slow-motion roll calls that the Senate uses to bide time.

These procedures, called “quorum calls,” usually serve no other purpose than to fill up empty minutes on the Senate floor. They are so boring, so quiet that C-SPAN adds in classical music: otherwise, viewers might think their TV was broken.

This year — even as Washington lurches closer to a debt crisis — the Senate has spent a historic amount of time performing this time-killing ritual. Quorum calls have taken up about a third of its time since January, according to C-SPAN statistics: more than 17 eight-hour days’ worth of dead air.

On Thursday, the Senate was at it again. At least on “Seinfeld,” doing nothing came with a funky bass line.

“It’s not even gridlock. It’s worse than that,” said Allan Lichtman, a history professor at American University who once ran for the Senate himself as a Democrat. He said “gridlock” implies that somebody was at least trying to get legislation passed.

Instead, he said, this year “they’re not even trying to get something done.”

To an outsider, a quorum call looks like a serious — if dull — piece of congressional business. A clerk reads out senators’ names slowly, sometimes waiting 10 minutes or more between them.

But it’s usually a sham. The senators aren’t coming. Nobody expects them to. The ritual is a reaction to what the chamber has become: a very fancy place that senators, often, are too busy to visit.

This is what happened: Decades ago, senators didn’t have offices. They spent their days at their desks on the Senate floor. So clerks really needed to call the roll to see if a majority was ready for business.

Now, senators spend much of their time in committee rooms, offices and elsewhere. If no big vote is on the horizon, often nothing at all is happening on the Senate floor.

But Senate rules don’t allow for nothing to happen. That would require a formal adjournment, which would mean lots of time-consuming parliamentary rigmarole.

Instead, the last senator to speak asks clerks to fill the time by calling the roll.

“It’s just a matter of keeping the store lights on when the customers aren’t there,” said Donald A. Ritchie, the Senate’s official historian. The procedures are much less common in the House, where the rules allow for a pause in activity without a formal adjournment.

On Thursday morning, Sen. Orrin G. Hatch (R-Utah) finished talking about an airman who was killed in Afghanistan. He looked around, realized he was alone, and suggested a quorum call.

“Mr. Akaka,” the clerk intoned.

Hatch left the floor. Minutes passed. It was so quiet that, when a page carried out a glass of water, the clink of the ice cubes could be heard up in the gallery. Tourists watched blank-faced. Ten minutes passed. Some of the visitors got up to leave.

After 12 minutes, Sen. Mark R. Warner (D-Va.) showed up. “I ask that the proceedings of the quorum be dispensed with,” he said. That’s how quorum calls usually end: The next senator who wants to speak asks for a halt.

After Warner gave a brief speech on the value of federal workers, it happened again. “Mr. Akaka,” the clerk said. Twenty-one minutes of silence.

At a deli in the Senate’s basement, it was clear this was wearing on people. One Capitol employee asked another: Where are you working today? “Senate chamber,” his buddy replied. “Shoot myself in the head.”

These sham roll calls have been a feature of Senate debate for decades, but this year has been special: According to C-SPAN, the Senate has spent more than 32 percent of its time in quorum calls. That’s more than in any comparable period dating to 1997.

The main reason seems to be the bare-bones agenda pursued by the Senate’s Democratic leaders: There have been just 87 roll-call votes so far, compared with 205 in the same period during 2009. Senate Democrats have not even proposed an official budget; the strategy appears to be to shield vulnerable incumbents from controversial votes on spending.

“Why are we here?” asked Sen. Tom Coburn (R-Okla.), a critic of the large number of quorum calls this year. “The Senate is not operating the way it was designed, because politicians don’t want to be on record.”

Democrats, on the other hand, say they haven’t brought up much legislation because they think Republicans will just block it.

“You always hope it’ll get better,” said Jon Summers, a spokesman for Senate Majority Leader Harry M. Reid (D-Nev.).

It might. There is an upcoming deadline to lift the national debt ceiling, and that could produce major legislation later this summer.

But not yet. This year, in fact, C-SPAN worries that its library of classical background music has been over-used. It is trying to expand its options, within a set of strict conditions: The music must be “calm and benign.” No cannon-booming “1812 Overture.” No funeral marches.

And it must not imply any comment on the nothingness happening onscreen. The Capitol Hill newspaper Roll Call recently suggested Lady Gaga’s “Bad Romance.” Non-starter.

C-SPAN has also started using a graphic showing tweets from members of Congress. It’s a signal that lawmakers are doing something. Just not here.