Scott Thompson / Maryhill Museum file

Maryhill Museum's concrete replica of Stonehenge was designed to duplicate the ancient English monument.

British researchers conducted experiments at a Stonehenge stand-in as well as the actual 5,000-year-old monument to determine how sounds echoed within the ancient circle of stones — and they found that the sounds would have taken on an eerie reverberation.

"We can expect such a space to have a striking effect on someone of that time, identical to what we feel nowadays when we go into a church," the University of Salford's Bruno Fazenda, who orchestrated the research project, told me in an email.

The study is described on the university's website in a technical analysis as well as a news release issued last week, but the upshot is that the Neolithic people who gathered inside the circle could well have had a religious aural experience. That meshes with the view of most archaeologists that the monument on England's Salisbury Plain took on the trappings of a place of healing — a "Neolithic Lourdes," if you will.

It's not easy to reconstruct the sounds of ancient Stonehenge: For one thing, many of the standing stones are missing from what was thought to be their original places, ruining the acoustic arrangement. For another thing, researchers are not allowed to run electrical power out to the site, or bring in a generator. That limits the types of sound equipment and scientific instruments that can be used on site.

Replicating the reverb
Fazenda and his colleagues from the University of Huddersfield and the University of Bristol found a couple of clever solutions to those challenges. They brought air-filled balloons to the Stonehenge site in 2009, then popped the balloons with a needle and recorded the reverb with a microphone and a digital field recorder. The reflected sounds of the pops were hard to make out, but they appeared to follow a pattern of 1-second reverberation time at midfrequencies, for locations that were within the ruins of the stone circle.

To study the reverberation patterns in detail, the team headed off to the Maryhill Museum in Goldendale, Wash., which has a full-scale concrete replica of Stonehenge on its grounds. The monument was built by millionaire industrialist Samuel Hill as a tribute to fallen World War I servicemen. The museum let the researchers make their measurements with more sensitive instruments, powered by on-site generators. The same balloon-popping technique was used, and the readings confirmed the reverberation pattern that the team found at the real Stonehenge.

"For an outdoor space, the stone circle exhibits quite a 'live' acoustic environment," Fazenda said. "In the Neolithic, such an environment was not very common at all. The only spaces that might sustain reverberation were caves and perhaps some natural features such as opposing cliff faces."

Fazenda said the echo effect would be much more like what you hear in a cathedral than in a concert hall.

"The center of the space has potential for some focusing effects," he said. "That's the point where all reflections arrive at the same time, and with the largest gap relative to direct sound. On paper we would expect that to sound striking. However, there are quite a lot of scattering effects from the stones, so the clear echoes are somewhat destroyed by it."

He stressed that it's not at all clear whether Stonehenge was designed with the acoustics in mind, but he and his colleagues do think that the setting would have added a special something to drumbeats, chants or music inside the stone circle.   

'Research hobby'
Fazenda, who teaches audio production at Salford, has been working on this project for the past four years on an unfunded basis. "It has been a kind of 'research hobby' that I have managed to do after hours (don't really call it spare time)," he wrote. He believes the project could break new ground in the field of archaeoacoustics — the study of the sound characteristics of ancient spaces.

"The original focus was on studying the acoustic response of the space," he said. "The recent output has been that we replicated it using wavefield synthesis, which immerses you in a sound field, thus giving you the most approximate aural experience that you could get of being in the space. That was shown at a few recent events, and we have a permanent demo in our labs here at Salford. A wavefield synthesis system uses +64 channels and speakers, so it is not really portable."

Such a system can be tuned to provide a virtual-reality sense of the sounds of Stonehenge, as well as the sounds of other ancient settings that are no longer configured the way they were in their heyday. Want to hear the roar of the crowd in the Roman Colosseum? There's a wavefield synthesis app for that.

Fazenda is preparing a paper on his "research hobby" for Acta Acustica, the journal of the European Acoustics Association. He's also writing a chapter for a book on the acoustics and music of British prehistory. (For more on that subject, check out the website of the Acoustics and Music of British Prehistory Research Network.)

You can expect to hear more about the sounds of Stonehenge in the months and years ahead. In the meantime, give a listen to these sound files, and follow the Web links for more about archaeoacoustics.

Stonehenge sound files:

• Hand-clapping outside and inside the Maryhill stone circle (via Sonic Wonders)
• Univ. of Salford's rendering of a song with Stonehenge-style reverb (WAV file)
• Sounds of Stonehenge ... including a podcast on sound heritage

More about archaeoacoustics:

• Scientists revive sacred sounds
• Was Stonehenge inspired by a sound illusion?
• It turns out that cavemen loved to sing
• Stonehenge: Totally awesome place for raves
• Researchers re-create scary pre-Columbian sounds
• Acoustic archaeology yields mind-tripping tricks
• Listen to the sounds of science

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

NASA file

Astronauts on Mars would probably speak with each other on the surface through radio links — but if they were to pick up voices or sounds transmitted through Martian air, would they sound different? Acoustics experts say they would.

If you could speak on Venus, you might sound like a deep-voiced Smurf — while on Mars, your voice could have the shallow ring of a higher-pitched Shrek. And if you enjoy the sound of a waterfall on Earth, wait until you hear what that tinkling would sound like on Titan. Researchers at the University of Southampton have simulated all these sounds, based on the physics of planetary atmospheres.

"This is the real deal," Tim Leighton, an acoustics professor at the British university, said in a news release. "It's as close as we can get to the real sound of another world until a future probe or astronaut actually goes there and listens to what it really sounds like."

The sounds are being shown off over the next week at the Astrium Planetarium at INTECH, near Winchester, as part of a show titled "Flight Through the Universe."

"Hearing the sounds communicates ideas about the different atmospheres and highlights the sheer alienness of the other worlds in our solar system," planetarium manager Jenny Shipway said. "There is interest in this software from other planetariums worldwide, and we're very proud to be hosting this world first."

Simulation software
Leighton and his colleagues have been developing the audio simulation software for years, in part to determine what sounds a Titan probe might record if it were to splash down in a lake of hydrocarbons during a future space mission. The software can tweak the pitch and timbre of sounds ranging from thunder and whirlwinds to music and the human voice, depending on atmospheric composition, pressure and fluid dynamics.

"On Venus, the pitch of your voice would become much deeper," Leighton said. "That is because the planet's dense atmosphere means that the vocal cords vibrate more slowly through this 'gassy soup.' However, the speed of sound in the atmosphere on Venus is much faster than it is on Earth, and this tricks the way our brain interprets the size of a speaker."

He suggests that our brain has been fine-tuned this way "to work out whether an animal call in the night was something that was small enough to eat, or so big as to be dangerous." On other planets, however, that fine tuning can lead to different impressions.

"When we hear a voice from Venus, we think the speaker is small, but with a deep bass voice," Leighton said. "On Venus, humans sound like bass Smurfs."

He said the situation would be different on Mars. "The lower sound speed on Mars does not lower the pitch of the voice," Leighton told me in a follow-up email. "It makes the speaker seem slightly larger, but still in pitch. In fact, the atmosphere of Mars would raise the pitch of the speaker's voice slightly, because of a density effect."

Microphone missions
Other groups have produced simulations of extraterrestrial sounds, based on their own assumptions about atmospheric effects. The nonprofit Planetary Society actually helped set up experiments to record and send back sounds from the Martian surface — but one mission that carried the Mars Microphone failed (Mars Polar Lander, in 1999), while a French mission that was due to carry another microphone was canceled (Netlander). NASA's Phoenix Mars Lander had a small microphone on its Mars Descent Imager, but it produced no data during that 2008 mission.

Leighton told me he didn't think the Planetary Society's simulated sounds were quite right, and he sent along a sampling of his own simulations. The differences between the sounds are actually subtler than I expected them to be, except for the Titanian waterfall, which actually sounds pretty alien. See what you think after listening to these sound clips:

• A reading of "Mary Had a Little Lamb," Earth-style
• "Mary Had a Little Lamb" on Venus
• "Mary Had a Little Lamb" on Mars
• "Mary Had a Little Lamb" on Titan
•  Waterfall on Earth, and the simulated analog on Titan
• Simulated rumble of thunder on Earth, Mars and Venus
• Simulated crash of thunder on Earth, Mars and Venus
• Splashdown of probe in Earth lake and in Titan lake
• The simulated winds of a Martian dust devil

More about the sounds of space:

• Solar storm soundtrack recorded on video
• Video: Hear the sound of a black hole
• The sights and sounds of space

In addition to Leighton, the Southampton team members who are researching extraterrestrial acoustics include Professor Paul White and M.Sc. students Nikhil Banda and Benoit Berges. Leighton has also worked with Andi Petculescu at the University of Louisiana at Lafayette to study how voices and musical instruments would sound on other worlds.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

Researchers have re-created the love song of a katydid from 165 million years ago, based on an analysis of fossilized wings found in northwest China. They say the chirp adds an aural dimension to our picture of the forests of the Jurassic Era.

"The Jurassic forest was already packed with many animals singing at night," Fernando Montealegre-Zapata, a University of Bristol biologist who specializes in insect sounds, told me today. "I'm not just talking about the crickets but the frogs. That would create a noisy environment, and in a noisy environment the best way to communicate is with a single frequency, and loudly."

That assumption fits with the analysis conducted by Montealegre-Zapata and his colleagues, which appears in this week's Proceedings of the National Academy of Sciences. They started with a well-preserved Middle Jurassic fossil, one of several found by Chinese paleontologists at Inner Mongolia's Jiulongshan Formation. This particular fossil revealed the wing structure for a long-extinct species of katydid, also known as a bushcricket, which has been dubbed Archabolilus musicus.

In life, the bug would have had relatively large wings, measuring more than 2.8 inches (7 centimeters) in length, with broad stripes of color. Its closest living relatives include katydids (Tettigonidae) and grigs (Prophalangopsidae).

The researchers made detailed measurements of the fossil wing's parts, including the organs that katydids use to produce their mating calls. Scientists believe that ancient katydid, like their modern-day descendants, strummed their songs by rubbing the tiny teeth of one wing against a plectrum on the other wing.

For comparison's sake, Montealegre-Zapata and a colleague of his at the University of Bristol, Daniel Robert, analyzed the wing structures of 59 modern-day katydid species. They fed all those readings and the characteristics of the insects' songs into a mathematical model. Then they looked at where A. musicus would fit in that model.

Their conclusion, based on the size of the wing and the precise spacing of the teeth, was that the Jurassic katydid would emit a steady tone at a frequency of 6.4 kHz for 16 milliseconds. That was enough information to reconstruct the sound, which you can hear by clicking on the video button above.

T.J. Walker / Univ. of Fla.

Some of the closest modern analogs of the ancient katydid known as Archaboilus musicus are in the Cyphoderris insect family. This male specimen of the species Cyphoderris monstrosa was collected in Douglas County, Oregon.

The researchers' reconstruction has the calls coming less than a second apart, because that would be the typical frequency for species of katydids that are not threatened by bats. Paleontologists say bats were not a threat to Jurassic bugs because they didn't exist during that period.

The single-tone call would have come through loud and clear to other katydids, Montealegre-Zapata said in a news release.

"For Archaboilus, as for living bushcricket species, singing constitutes a key component of mate attraction," he said. "Singing loud and clear advertises the presence, location and quality of the singer, a message that females choose to respond to — or not. Using a single tone, the male's call carries further and better, and therefore is likely to serenade more females. However, it also makes the male more conspicuous to predators if they have also evolved ears to eavesdrop on these mating calls."

His guess is that the Jurassic katydid was a nocturnal creature, since all present-day katydids that use musical calls are nocturnal. That would have kept the crickets from being picked off by daytime predators such as the feathered, flying Archaeopteryx. But Montealegre-Zapata said they may have made tasty morsels for bug-eating Jurassic mammals such as Morganucodon and Dryolestes (which could conceivably hear the cricket calls).

The findings strongly suggest that katydids were well-adapted for music-making during the Middle Jurassic, 165 million years ago. That led the researchers to speculate that the katydid's distant ancestors might have begun chirping more than 50 million years earlier, during the Triassic Period, thanks to "the formation of random teeth across several veins on the forewings, and the associated production of noisy sounds."

Reconstructing the ancient song of a katydid could also help answer questions about modern-day insect communications, Montealegre-Zapata said. There's quite a bit of variation to the chirps of katydids and crickets, as you'll find out if you listen to the audio clips on this webpage. Over time, musical bugs may well change their tune to suit their biggest fans and frustrate their worst foes.

Montealegre-Zapata said the reconstruction of the Jurassic katydid's love song "suggests the evolutionary mechanisms that drove modern bushcrickets to develop ultrasonic signals for sexual pairing and for avoiding an increasingly relevant echolocating predator — but that only happened 100 million years later, possibly with the appearance of bats."

More about prehistoric sounds:

•  Duck-billed dinos had built-in sound systems
• Fossil shows traces of first modern ears
• Listen to the music of prehistoric flutes
• Interactive: When was the Jurassic Period?

In addition to Montealegre-Zapata and Robert, authors of the PNAS study, "Wing Stridulation in a Jurassic Katydid (Insect, Orthoptera) Produced Low-Pitched Musical Calls to Attract Females," include Jun-Jie Gu, Michael S. Engel, Ge-Xia Qiao and Dong Ren.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.