Secret Sounds of Stonehenge

30 08 2010

Trevor Cox reveals how the acoustic footprint of the world’s most famous prehistoric monument was measured 

 Echoes of the past: The sites and sounds of prehistory Just after sunrise on a misty spring morning last year, my fellow acoustician at the University of Salford, Bruno Fazenda, and Rupert Till of the University of Huddersfield, UK, could be found wandering around Stonehenge popping balloons. This was not some bizarre pagan ritual. It was a serious attempt to capture the “impulse response” of the ancient southern English stone circle, and with it perhaps start to determine how Stonehenge might have sounded to our ancestors. An impulse response characterises all the paths taken by the sound between its source – in this case a popping balloon – and a microphone positioned a few metres away. It is simply a plot of the sound pressure at the microphone in the seconds after the pop. The first, strongest peak on the plot represents the sound that travelled directly from the source to the microphone. Later, smaller peaks indicate the arrival of reflections off the stones. The recording and plot shows the impulse response Bruno and Rupert measured with a microphone positioned at the centre of Stonehenge and a popping balloon at the edge of the circle. This impulse response represents an acoustic fingerprint of the stones. Back in the lab, it can be used to create a virtual rendition of any piece of music or speech as it would sound within the stone circle. All that is needed is an “anechoic” recording of the raw music or speech – a recording made in a reflection-free environment such as the open air or, better, a specialist anechoic chamber such as we have at Salford. The anechoic recording and the impulse response can then be combined using a mathematical operation called convolution. We’ve done with with a recording of drumming: here is the anechoic original, and here it is convolved with the measured impulse response of Stonehenge. The difference is easily appreciable: there is more reverberation or ringing to the drumming sound thanks to the reflections off the stones. What’s more, the tonal balance of the sound is entirely different: it has become much deeper, as if the treble has been turned down.

Replica henge The popping of a balloon is not the standard or best way to measure an impulse response, but more sophisticated equipment was not allowed at Stonehenge. At a full-size replica of the monument at Maryhill, Washington state, however, Bruno and Rupert were able to use powerful loudspeakers and special test signals to get more accurate results. Maryhill also has the advantage that it is complete, whereas some of the stones of Stonehenge have fallen or disappeared over the years. That makes a noticeable difference to the drum sounds convolved with Maryhill’s impulse response: the more complete stone circle makes the sound echo for longer, with the extended reverberation being most noticeable after the last drum. Over many decades, a sophisticated understanding of how to interpret impulse responses has been built up. For example, we now know how features within the impulse response, such as the time it takes for reverberations to die away, relate to peoples’ perceptions of the nature of the sound. The hope is that by applying that expertise to ancient monuments such as Stonehenge, we can better appreciate their acoustical effects on our ancestors –and perhaps begin to answer the question whether these effects were the product of accident or design.

Sounding stones

We also know that our ancestors appreciated their ability to exploit their environment to make sound early on. The discovery of three flutes in 2009 in a cave in south-west Germany, the best preserved of them made from a vulture’s wing bone and containing five finger holes, pushes the origins of music back to the middle Palaeolithic era, 40,000 years ago.

Lithophones or rock gongs- stones that create a tone when hit- are found around the world. A cave at Fieux à Miers in the Midi-Pyrénées region of the south of France contains a 2-metre-tall feature which resonates like a gong when struck. Recalcified fractures on the lithophone indicating where it was struck can be dated back to the upper Palaeolithic, around 20,000 years ago (Oxford Journal of Archaeology, vol 4, p 31). Outdoor examples include Kupgal Hill in Karnataka state, southern India, where an outcrop of dolerite boulders emits loud ringing tones when hit with granite stones. Nicole Boivin of the University of Oxford suggests that shamans might have used the rock gongs during formal rituals. Dating the wear marks in boulders is impossible, but the presence of Neolithic rock art indicates that the site was used for many thousands of years (Antiquity, vol 78, p 38).

Imagery such as cave paintings, markings or etchings also provides tantalising clues to how prehistoric humans might have exploited their surroundings to make sound. Iegor Reznikoff of Nanterre University, Paris, has examined the caves of Rouffignac in the south of France and showed that paintings are located where the most interesting sound effects are heard. Devereux, in his book Stone Age Soundtracks, cites numerous other examples around the globe of seemingly premeditated placing of petroglyphs or pictographs, including sites where art is painted on concave rock walls that give distinct echoes.

Merlin @ Stonehenge
The Stonehenge Stone Circle Website





Stonehenge Tourism update

19 08 2010

“So what are we going to do about it?” Here’s one answer, David
Delighted to see that David Cameron is such a strong supporter of tourism. We have a long way to go to break the cultural snobbery that separates the staples of the UK industry – catering, accommodation, tour guides, campsites, postcards, guidebooks, souvenirs and so on – from middle class respectability. It’s better than it was, but sometimes it seems that the shame of engagement can only be tempered by calling it art, and littering the countryside with half-baked works whose cost might have been more creatively and productively deployed by addressing the needs of tourists instead of interfering with their experiences.

Anyway, as Cameron said in his speech yesterday, “Tourism is a fiercely competitive market, requiring skills, talent, enterprise and a government that backs Britain”. This was set in the context of the 2012 Olympics – as was the new visitor centre for Stonehenge when proposed by the last government.

What with Snowdonia, Devon and Cornwall, the Lake District, Norfolk, the Inner Hebrides, the Highlands of Scotland, the canals of Staffordshire, Oban, Llandudno, Torquay, Deal, “our historic monuments, our castles, country houses, churches, theatres and festivals… beautiful beaches… national parks, our hundreds of historic gardens and national network of waterways… our museums [including the British Museum, the National Gallery and the [sic] Tate Modern]… Glyndebourne and Glastonbury… the Bristol Old Vic and the Edinburgh Fringe. The Bodleian Library and the Hay literary festival. Ascot and the Millennium Stadium; Nelson’s column and the Olympic Park’s Orbit” – phew! – Cameron had no time to mention Stonehenge.

But I’m sure he had Stonehenge in mind, not least when he praised John Penrose, minister for tourism and heritage for the skills he brings to the job. After the Treasury took such pleasure in June in claiming to cancel the Stonehenge project – an action in fact not within its powers – it was sensitive of Cameron to avoid mentioning the stones. So let’s say it for him.

• Stonehenge is one of the world’s most recognisable icons of cultural history (“When I asked what England meant to them, the answers went: Stonehenge, Harry Potter, fish and chips…”: Blake Morrison talking to Japanese schoolgirls in 2002).

• Stonehenge is one of the UK’s most popular and must-see tourist destinations, attracting around a million visitors a year, of whom 50–60% are international.

• Stonehenge’s present state has long been agreed by parliament and international commentators to be a disgrace.

• An imaginative, creative plan to transform visitors’ experiences – from access and parking to a new museum, toilets and cafe – and Stonehenge itself, by removing roads nearby, has planning consent and is ready to start.

• This plan was designed to be cheap and cost-effective by the previous government, after it dropped a more ambitious scheme, and ready in time for the 2012 Olympics. But now that the Treasury has withdrawn its promise of £10m, it needs new sources of funding to happen.

• Stonehenge is Stonehenge. Picture Post put it on its cover in 1947 to lead an issue devoted to the post-war crisis. Stonehenge could now be a symbol for us and the world, of reflection, regeneration and creativity in the face of  the modern crisis.

“Can we seize the opportunity”, said Cameron, “of this great decade of sport – and especially the Olympics – to deliver a lasting tourism legacy for the whole country and not just here in London?”

Stonehenge awaits.  Mike Pitts

Merlin @ Stonehenge
The Stonehenge Stone Circle Website





Tonight at Stonehenge will be best night in five years to view spectacular Perseids meteor shower

12 08 2010

Stonehenge Landscape in Wiltshire – Step back in time and discover the ancient skies of Salisbury Plain’s chalk downlands, home to the impressive prehistoric stone monument
It is also one of the most awe-inspiring sights in the heavens that you can view from your own back garden.

And now scientists say that star-gazers are in for a treat this week with clear skies expected to give fantastic views of the spectacular Perseids meteor shower.

Experts say that with the moon in its ‘new’ phase and clear skies this week could mean that it’s the best year since 2007 to catch the spectacular show.

The annual Perseids meteor shower ) at Friars Crag, Derwentwater, Keswick, Cumbria in 2008. Astronomers predict this year will be the best display yetThe annual Perseids meteor shower ) at Friars Crag, Derwentwater, Keswick, Cumbria in 2008. Astronomers predict this year will be the best display yet

The phenomenon, which happens each summer as the Earth’s orbit takes it through debris scattered by the tail of Comet Swift-Tuttle is expected to peak on Thursday night.

Amateur astronomers were left disappointed last year after clouds ruined the expected view.

The Taurids are named after the constellation Taurus, because their paths can be traced from that area of sky.

On the night of the 12 August the new moon’s thin crescent will have set in the early evening, leaving a dark sky for the meteor shower, promising a stunning show of shooting stars.

For the best views, star gazers are advised to escape the city lights and head out to the big open and dark skies of the countryside where the stars and meteors will be at their brightest.

SEVEN BEST PLACES IN UK FOR SEEING THE PERSEIDS

Black Down in Sussex – Get closer to the stars on the highest point in the South Downs, just over a mile from the town of Haslemere

Teign Valley in Devon – Discover the stars at this Trust property within Dartmoor National Park and close to Castle Drogo

Penbryn Beach in Wales – Beautiful, unspoilt mile-long beach on the Ceredigion coast in west Wales, great for a bit of star gazing and a late night paddle

Stonehenge Landscape in Wiltshire – Step back in time and discover the ancient skies of Salisbury Plain’s chalk downlands, home to the impressive prehistoric stone monument

Wicken Fen National Nature Reserve in Cambridgeshire – Close to historic Ely, the wild landscape of the National Trust’s oldest nature reserve offers dark skies and a wealth of nocturnal wildlife to listen out for

Mam Tor in Derbyshire – Escape the bright city lights of Sheffield and experience the peace and tranquillity of Mam Tor’s dark skies in the Peak District

Friar’s Crag in Cumbria – Surrounded by the breathtakingly beautiful scenery of the Lake District, Friar’s Crag in Keswick juts out into the spectacular lake of Derwentwater

The Met Office is predicting that the clearest skies on Thursday night are likely to be in southern and western parts of England and Wales.

Nasa scientists also claim that this ‘promises to be one of the best displays of the year.’

‘If forecasters are correct, the shower should produce a peak display of at least 80 meteors per hour,’ they say.

Jo Burgon, Head of Access and Recreation at the National Trust, said: ‘Seeing the stars in  their full splendour, shining bright in the sky above you, is one of the unofficial wonders of the natural world. 

‘The intrusive glow of street lighting or a bright moon can be detrimental to a good meteor experience.

‘But with a good weather forecast, this year’s Perseids display could be a cracker, and not one to be missed.’

Some of the locations highlighted in the National Trust guide include the dramatic landscape around the world famous Stonehenge in Wiltshire and Mam Tor in the Peak District, high above Sheffield and only a short distance from the city of steel.

Jo Burgon, added: ‘Its worth spending the time to find the perfect spot to gaze up at the stars; as once you’re there looking into the night sky it will take your breath away.

‘And the best thing is that it won’t cost you a penny and this star time will always stay with you as one of those experiences that money can’t buy.

Emily Winterburn, author of The Stargazer’s Guide, said: ‘The Perseids are a great meteor shower to watch. 

‘The nights aren’t too cold and for once, thanks to the moon, the summer nights are dark enough to make even the dimmer meteors visible to the naked eye.’ 
As usualy Histouries UK Tours will be operating guided tours of Stonehenge and Avebury tonight, I joined them last year and it was awesome!

Merlin @ Stonehenge
The Stonehenge Stone Circle Website





‘Fantastic’ dig ends at Marden Henge in Wiltshire

9 08 2010

A 4,500 year-old dwelling was uncovered at the dig
Excavation work has finally come to an end at prehistoric site, Marden Henge near Devizes.

It was the first investigation of the site since 1969.

Marden Henge no longer has any standing stones and is said to be one of Britain’s least understood ancient sites.

The dig, which began six weeks ago, uncovered all manner of neolithic treasures including a 4,500-year-old dwelling as well as pottery, flint and bones.

Archaeologist Jim Leary from English Heritage said the findings were very significant.

“The level of preservation is just phenomenal,” he said.

“We don’t have a comparison in England. We could never have imagined we would come across this.”

The level of preservation is just phenomenal. We don’t have a comparison in England. We could never have imagined we would come across this

Jim Leary, English Heritage
The world’s media has descended on the site throughout the duration of the excavation work.

Jim said: “It’s fantastic and I think it really shows how people are engaged with their heritage and their land. It’s really important at this time that archaeology can engage people and give something back.

“As archaeologists, we have to let people know what we’ve found. We’re doing this for the public, we’re telling them all about it, and that’s why archaeology is so important.”

Fellow English Heritage archaeologist, Paddy O’Hara said of the building they uncovered: “It’s just unparalleled. I’ve never seen anything like it at all apart from Skara Brae in the Orkneys. The preservation of this building is just superb.

“I was here about a fortnight ago and I was, quite frankly, sort of sceptical. People were saying ‘oh, maybe there’s a building here’, but I really wasn’t convinced.

“Just walking up here now, the thought that I could have missed this would have been heartbreaking, as it’s just a fantastic bit of archaeology.

“It’s really, utterly fabulous.”  HisTOURies UK – Tour Guide

Merlin @ Stonehnege
The Stonehenge Stone Circle Website








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