“According to the legend, witches were women with magical knowledge that with the use of herbs cured illnesses and performed spells. In 1639, the book “De Nuce Maga Beneventana” described how the place where the “witches” gathered was an area south of the city of Benevento in South Italy in a long and narrow gorge. This valley with high rock walls was called the “stretto di Barba”. According to the legend, under a walnut tree in the “stretto di Barba”, the Longobards were used to perform sacred rituals. To make the rituals more effective, the sounds were amplified by the narrow gorge with flat and parallel rock walls”. Researched and recorded by Gino Iannace, Umberto Berardi, and Amelia Trematerra. (URL: [researchgate.net/publication/328378258_The_acoustics_of_the_Witches_Valley](http://researchgate.net/publication/328378258_The_acoustics_of_the_Witches_Valley))

The Witches Valley

[Sound mirror](https://webapps.kent.gov.uk/KCC.ExploringKentsPast.Web.Sites.Public/SingleResult.aspx?uid=TKE972) built in 1928 near the edge of Abbot's Cliff as part of a number of acoustic mirrors along the Kentish Channel cost. There was a timber operator's [shed](https://webapps.kent.gov.uk/KCC.ExploringKentsPast.Web.Sites.Public/SingleResult.aspx?uid=TKE747) on the west side of the mirror but all traces of this [building](https://webapps.kent.gov.uk/KCC.ExploringKentsPast.Web.Sites.Public/SingleResult.aspx?uid=TKE600) ahve now gone. The sound mirror system was abandoned in 1938 in favour of RADAR. The mirror exsists in good condiditon. -

Kent County Council

Abbot’s Cliff Sound Mirror

**Imagine a sonic artefact arriving from an unknown space and time. *At the Threshold* takes the listener on a journey through the dichotomous architecture of a conch shell, encountering acoustic anomalies told through feedback loops, field recordings and a constructed chorus of the artist’s own voice and that of a digital surrogate at various stages of machine learning.**

At the Threshold

A Norman, Gothic, Gothic Revival style cathedral built between 1220 and 1877 in Bristol.

Bristol Cathedral, The Elder Lady Chapel

The “Comunale - Pavarotti” Theatre (Modena -Italy) was recorded by Enrico Armelloni and Adriano Farina as part of the  Sipario project.  Impulse Responses were recorded by the 32 microphones of the Eigenmike, (A-format), next converted from A-to-B format using Gary Elko's (MH Acoustics) plugin encoder, they are "3rd order" and lastly converted to "1st order". 

The dodecahedron was placed in the Center position on the stage and then measured in three stalls positions.

Comunale-Pavarotti Theatre

IM thermoelectric cooling tower in Charleroi, Belgium. The cooling tower is a precast concrete structure in the shape of a truncated cone. It has dimensions of 60 meters in diameter at the base and 45 meters at its peak, reaching a height of 75 meters. Its function was to cool water during the coal combustion process. It had a capacity to cool 480,000 gallons of water per minute, which was drawn directly from the adjacent river. Its reverberation time T60 is 15 seconds. The Charleroi thermoelectric plant was originally built in 1921, it was one of the largest coal-fired power plants in Belgium. In 1977, the plant was the main source of energy in the region. The thermoelectric company was responsible for 10% of the total CO2 emissions in Belgium. Due to this, and due to Greenpeace protests in 2006, the plant closed in 2007.

Cooling Tower - IM Power Plant

Hidden away and mysterious, with beautiful reverb.  We positioned the microphone marked with a red dot in the chamber past the Second Chamber.  As you can see on the survey, the cave continues much deeper.  After this ‘third’ chamber, the tunnel gets very narrow and tricky to move with equipment. In this schematic, the microphone (M1) is indicated in red and source positions (S-2 - S7) are indicated in green. The current listening order corresponds to the round thumbnail images from left to right: S1; S2; S4; S7.

Dowkerbottom Cave

Earth Echo

Ely Cathedral, UK

Entrapped - Rob Brinkworth

“The Cumaean Sibyl cave is a mythological place in the north of Naples, where the Sibyl, a priestess presiding over the Apollonian oracle, received the travelers and predicted their future. The cave is length about 140 m, with trapezoidal section excavated in the rock of tuff. The cave has a height of about 4.5 m and it is 2.4 m wide. The legend says that the Sibyl received the travelers in the final part of the cave. Acoustic measurements were done with an omnidirectional sound source in the in the room inside the Sybil cave while positioning the microphones along the cave.” Prof Gino Iannace & Umberto Berardi

Ether Echo - Dorit Chrysler & Cobi van Tonder

The Forn space is an original ceramic kiln located in the Catalan city La Bisbal d'Emporda belonging to the Terracota de la Ceramica museum. "El Forn" space The central axis of the museum's internal circulation is formed by the four inverted flame furnaces. The four have valued heritage and have been incorporated into the permanent exhibition as basic pieces to explain the process of ceramic firing. Three have been musealized (one of them is empty, the second is loaded with work and the third shows an audiovisual that explains the cooking process), while the fourth has been transformed into a space for temporary exhibitions: "El Forn". With a biannual periodicity, the space (reduced: about 15 m2) is designed to exhibit well-chosen ceramic pieces from both private and public collections.

Forn Terracotta Museu de Ceramica

Galli Theatre

Listen to the acoustics of the “Teatro Grande” of Brescia, Italy.

Great Theatre

Great hall of Binche (1549) archaeoacoustic reconstruction:

A simulated Binaural Impulse response from inside a historic palace. It is the result of an archaeoacoustic reconstruction.

Great hall of Binche 

Hallgrímskirkja is a Lutheran parish church in Reykjavík, Iceland. At 74.5 metres tall, it is the largest church in Iceland and among the tallest structures in the country. The church is named after the Icelandic poet and cleric Hallgrímur Pétursson (1614–1674), author of the Passion Hymns.

Hallgrímskirkja

This acoustic fingerprint is part of the OpenAirLibrary (openairlib.net), Audiolab, University of York, Damian T. Murphy.

The Hamilton Mausoleum, Hamilton, Scotland, was built for the 10th Duke of Hamilton, 1842 - 1858. It is constructed of marble and sandstone and is surmounted by a dome 36m in height.

The construction materials, size, shape, and dimensions of the latter result in a complex, dense, and very long reverberation. The interior of the Hamilton Mausoleum is approximately octagonal in plan, with a diameter of 18 m. Each side of the octagon is either a plane wall or a further semicircular alcove. The microphones were placed in the centre and the source placed to one side, just outside one of the alcoves, giving a source-receiver distance of 4.8 m.

Hamilton Mausoleum

**Inchindown Oil Tank Nº 1**

The Inchindown Oil Tanks are an underground oil depot in Invergordon, Ross-shire, Scotland, built for war purposes. They hold the record for the longest recorded reverberation in any human-made structure.

The site was officially named "Inchindown, Royal Navy Fuel Tanks" and was also known as "Invergordon Oil Fuel Depot". The complex consisted of six tanks: five were 237 meters long, 9 meters wide, with arched roofs 13.5 meters high; a smaller sixth tank was the same height and width but shorter. Work on the tanks began in 1938 and was completed in 1941. They were built to be a bomb-proof fuel supply for the UK Royal Navy base at Invergordon.

The tank explored corresponds to tank No. 1, built entirely of concrete. It is accessed through a tunnel 200 meters long, 2 meters high and 1 wide, built of concrete and in some sectors of live rock. To enter the tank it is necessary to go through a steel tube 45 centimeters in diameter and 3 meters long. It is currently completely empty and visits are restricted due to the danger of falling rocks and falls due to the large amount of oil that remains. The space has a T60 reverberation of 75 seconds, being the longest recorded in history.

Inside the tank, measurements were made of impulse response, frequency sweeps, vocalizations, found object percussion, and slow feedback. The sounds generated inside the tank escape any logic that we have ever been able to experience, each movement, each word stayed inside the space coming and going in a way where it was almost impossible to have a conversation. Inside the tank there was oxygen, but the smell of petroleum persisted and the darkness was absolute, the flashlights struggled to illuminate the black surfaces and if you stayed in one place for too long your boots melted into the black paste. It could be said that a saturation of the senses was generated, due to the sound, but also due to the strong darkness, a feeling of oppression that was maintained for the two hours that we remained inside. Somehow the tank had engraved in its atmosphere the energy of oil and the war for which it was used.

Inchindown, Tank Nº 1

A large part of the Ingleborough Cave system that we worked in was actually an underwater river, the whole 500m stretch is visually exhilarating. As one walks down the curving tunnel the last 100m of the area accessible to the public sounds the most enticing. This is the area named 'Long Gallery, '2nd Bells', 'Skittle Alley' and 'Pool of Reflections'. The play of light, darkness, echo, reflections, shapes and sound is mesmerising.  The connected underground otherworldly network of tunnels, halls and passageways has a tranquility and magical atmosphere, far away from our everyday reality and immerse the senses completely.

Thanks to Mariana Lopez for operating the Sound Devices and Richard Carter for aerial photography and additional photography. Thanks to Andrew Jarman, Ingleborough Cave management, for their support and for giving us access to take measurements in this amazing underground cave.

Ingleborough Cave

Ionion Mirror (part 1): This location in the sea was a tragic site where refugees drowned. A performance video/sound piece was created from this exact point in the water with sounds and video from above and under water (Cobi van Tonder). The acoustics are currently presented as an impression rather than via the standard impulse response methods of taking acoustic measurements. Sing into this space to hear the resonances from the drone music. A short distance from this point is a tiny little island called Zeus, seen in the reflection of the mirror.  Thanks to Ionion Art Centre.

<https://seas.ionionartscenter.gr/seas-arts-program/>  

Ionion Mirror

Joan Miro's Flood Cistern

The rainwater regulation tank is in use and is one of the seven tanks where the rainwater of the city of Barcelona accumulates. Due to the climatic changes that have occurred in the last century, mainly due to the high emission of greenhouse gases, which have raised the temperature of the planet, it rains more sporadically but the rains have become more intense, which has increased the risk of flooding. This has made it necessary to build these infrastructures to store water in case of flood risk.

The Joan Miró rainwater tank is located next to Plaza España, under the Joan Miró park. It occupies a total area of ​​approximately 6,500m2 and consists of two bodies for a total retention volume of 55,000m3.

We had the opportunity to enter the rainwater tank for an hour, with many restrictions, because it is a risk area. The space is presented as a large hypostyle hall, with a total of 175 pillars of 50 centimeters in diameter by 5 to 10 meters high. Inside the place, the murmur of the water coming from the city's underground channels was constantly felt, along with the urban noises that filtered through the air intakes. Within the space, measurements of the space's impulse response, slow feedbacks, frequency sweeps, and soundscape recordings were made. It should be noted that the space, due to its rectangular proportions and the presence of pillars, generated a wide series of harmonics.

Joan Miro's Flood Cistern

Kraftwerk, Berlin. Room Impulse Response from Ableton Live IR collection. We think it’s been recorded by Matt Jackson and Christian Kleine.

Kraftwerk

The Tvísöngur Sound Sculpture designed by German artist Lukas Kuhne is situated in the mountains above Seydisfjordur, northeast Iceland. This mushroom-looking concrete sculpture consists of interconnected domes in different sizes. Each one of the domes has a resonance that corresponds to a tone in the Icelandic musical tradition of five-tone harmony and it serves as Helmholtz resonators, as the wind blowing in off the cliffs rushes into and across the openings, the air within the structure resonates.

Lukas Kuhne Tvísöngur Sound Sculpture

This acoustic fingerprint is part of the OpenAirLibrary collection (openairlib.net), Audiolab, University of York, Damian T. Murphy.

Maes-Howe, Orkney, is one of the finest chambered cairns in Europe, and is dated to 3000BC. Prior work in the acoustics of ancient sites explores how the resonances exhibited therein might have affected regular human ritual and interaction with the space. It has been hypothesized that as these resonances are within the lower male vocal range, they may have been used in ritual to accentuate aspects of the voice. Unlike many similar ancient structures that have been studied to date, Maes Howe lends itself to the presence of strong modal frequencies. It is almost cubic in shape, of dimension 4.6m, with walls made from large, flat slabs of stone, resulting in smooth reflecting surfaces rather than more commonly found irregular placement of smaller stones.

Maes-Howe Cairn

Masini Theatre

Melissani Cave is located on the island of Kefalonia, in the Ionian Sea. In Greek mythology, Melissani was the Cave of the Nymphs. It features a lake surrounded with trees and forest, and is located east of the mountains of Evmorfia and Agia Dynati. The Ionion Art Centre, Kefalonia is making work here possible. The RIR here is imaginary/artistic - no actual measurements were conducted (as of yet) - as this project has been delayed due to travel restrictions. The reverb was extracted from cutting off the tails of other recordings made on a boatride in Mellisani and edited together to form an impression.

Mellisani Cave

The Cercs Mine Museum (Catalan: Museu de les Mines de Cercs) is a museum dedicated to coal mining, located in the Sant Corneli colony, in the Cercs municipal area, in the region of El Berguedà. It is a technology and history museum that describes the relationship between coal and the geological environment, the landscape, the economy and the people of L’Alt Berguedà

Mines de Cercs

Listen to your voice inside the “Municipale” Theatre, Piacenza, Italy.

Municipale Theatre, Piacenza

## The old Asland cement factory is a unique architectural work of the first magnitude. It is an impressive modernist building, which highlights the use of the construction technique of the Catalan vault (or flat brick) and wrought iron structures. The complex has a spectacular structure, since a staggered construction was chosen from the quarry to the level of the train, adapting to the unevenness of the terrain in order to take advantage of the force of gravity -fall due to inertia- in the manufacturing process of the cement.

Museu del Ciment de Castellar de n'Hug

**Natasha Barret - PRESENCE / NÆRVÆR (extract).**

**Outdoor, site-specific sound installation composed and produced by Natasha Barrett.**

**Location: Outside the Resistance Museum, Akershus Fortress, Oslo.**

**Throbbing of the cruise ships in the habour**

**Other harbour and construction site sounds**

**Resonances from the boats and city echoing around the fortress**

**Boat horns**

**The town hall bells (hour strikes as well as tunes).**

**Birds, dry leaves, adults and children, rain**

**Running over the cobble stones**

**The bi-annual air-raid siren test**

PRESENCE / NÆRVÆR (extract)

Pavarotti Theatre

**Iti composed and performed this piece based on a traditional Indian classical music scale played/sung in the early evening. It was recorded in by Rehan (Red Media studios) near** Aditya Vidyashram Residential School, Porayur**. Next auralised with the Taj Mahal impulse response and mixed by Cobi van Tonder.**

Raga Todi - Iti

The Cathedral Church of St Peter and St Wilfrid, known as Ripon Cathedral, and until 1836 known as Ripon Minster, is a cathedral in the North Yorkshire city of Ripon. Founded as a monastery by Scottish monks in the 660s, it was refounded as a Benedictine monastery by St Wilfrid in 672. The present church is the fourth, and was built between the 13th and 16th centuries. The cathedral is notable architecturally for its gothic west front in the Early English style, as well as the Geometric east window.

Ripon Cathedral


1. **Rokudan no Shirabe - Yatsuhashi Kengyo performed by Nora van Tonder**

\


Rokudan no Shirabe - Yatsuhashi Kengyo performed by Nora van Tonder

This work is part of the PhD thesis "Patrimonio Acústico de Teatros Romanos en España" by Angel Alvarez-Corbacho. More info, <http://www.sea-acustica.es/fileadmin/publicaciones/ASL-0_025_01.pdf>.

Roman Theatre of Regina Turdolorum

Set in a bay at the foot of high chalk cliffs this sand and pebble beach stretches for around 1.2km. Many rockpools, at low tide and hardly any beach at high tide.  Sea lions, gannets, oyster-catchers, gulls and eider ducks can all be found here. There has been a lighthouse near this spot since the 17th century.  The current structure, built in 1806, still guides vessels safely around the rocky headland.

Selwicks Bay

Sensory Feedback I

**Snømaskn**

**Chimera through time-space reflection. I had this idea to make something “impossible” - or unreal, as a “chimera”: an impossible appearance of sources originating in an electric or electronic process, in an acoustic atmosphere where they do not belong. The resulting space is an attempt to connect several different acoustic worlds through immaterial underground paths. To enter the imaginary space, listen to the piece: it starts with electronic drops, like morse signals from an unreachable space. The space builds up as the narrative develops around an interview with the snow maintenance company for railways, from processed news prep archive tapes from the 60s, that I process time-wise - thinking of “mirroring” as a timely process, time running back and forth, continuing into another subject about future space stations.**

**“Mais tu ne peux pas l’entendre,**

**la chimère aux yeux de rêve/de verre.**

**Et où disparaît la route**

**Quand la nuit tombe sur nous ?”**

\
**(*But you can’t hear it,***

 ***you’re the chimera with eyes made of glass/of dreams.***

***And where does the road disappear,***

 ***when night falls upon us?)***

**(Cikatri$, Quand la Nuit Tombe sur Nous)**

Snømaskn - Aurélie Ferrière

Spro Cave, Nesodden close to Oslo. Balloon pop recorded in centre of cave.

Spro Cave, Nesodden

The Taj Mahal is an ivory-white marble mausoleum on the right bank of the river Yamuna in the Indian city of Agra. It was commissioned in 1632 by the Mughal emperor Shah Jahan (r. 1628–1658) to house the tomb of his favourite wife, Mumtaz Mahal; it also houses the tomb of Shah Jahan himself. 

The Taj Mahal complex is believed to have been completed in its entirety in 1653 at a cost estimated at the time to be around 32 million rupees, which in 2020 would be approximately 70 billion rupees (about U.S. $1 billion). The construction project employed some 20,000 artisans under the guidance of a board of architects led by the court architect to the emperor, Ustad Ahmad Lahauri.

The Taj Mahal was designated as a UNESCO World Heritage Site in 1983 for being "the jewel of Muslim art in India and one of the universally admired masterpieces of the world's heritage". It is regarded by many as the best example of Mughal architecture and a symbol of India's rich history. (Wikipedia)

Taj Mahal

The Cumaean Sibyl

Verdi Theatre

Victoria Cave in Langcliffe, Settle.  

From a scientific point of view, many caves (e.g. Victoria Cave) are time capsules, with flora, fauna, bacteria, minerals and fossils that hold treasures from an immensely large timescale compared to human life on earth. Additionally, caves present themselves as archives for understanding peoples’ mythological landscapes and how they have evolved. Victoria Cave produced prominent artifacts, including evidence of the first humans in the Dales starting in 12,500 BC. It provides evidence that throughout the centuries of mortuary activities indicating that people used the Dales caves to mediate with the spirit world. By the Romano-British, AD 100 to 450 period, various Roman military accouterments were found inside of Victoria Cave was used as a shrine and there was a workshop area outside. If you feel like reading more, here are some references: Lord, T., et. al. (2017). The Pleistocene laminated sediments of Victoria Cave, North Yorkshire, UK: characteristics, age and significance. Cave and Karst Science. 44. 143-144. Lord, T., et al. (2012). A guide to work at Victoria Cave-from the 19'h to the 21" centuries. Cave Archaeology and Karst Geomorphology of North West England. Field Guide. 84-97. Otley, Jonathan., (1823). Guidebook, A Descriptive Guide of the English Lakes. Published by Kirky Lonsdale, Cumbria, 8th ed. 1849, 193; Lord, Tom & Howard, John. (2013). Cave Archaeology in the Yorkshire Dales.

 ![View from Victoria Cave](https://firebasestorage.googleapis.com/v0/b/acousticatlasdata.appspot.com/o/users%2FySEj7xpMKRhIETEPrBBqSEveD9o2%2Fimages%2F2f8dfd27-a004-4ae4-9553-d21218ebd896-BON_0355-min.JPG?alt=media&token=cf3d890b-564b-452c-a33b-2e2d8a4dacc1)

 ![The impulse responses for Victoria Cave were taken with in-ear binaural microphones and balloon pop.](https://firebasestorage.googleapis.com/v0/b/acousticatlasdata.appspot.com/o/users%2FySEj7xpMKRhIETEPrBBqSEveD9o2%2Fimages%2F5097eb06-4a90-4f32-9549-213e44fc2652-BON_0239.JPG?alt=media&token=01bd9b31-36f6-49f9-95fc-2496f621dd06)

 ![](https://firebasestorage.googleapis.com/v0/b/acousticatlasdata.appspot.com/o/users%2FySEj7xpMKRhIETEPrBBqSEveD9o2%2Fimages%2Faf68ddec-3152-4172-b29c-117a634ed933-BON_0217.JPG?alt=media&token=b56a7dbb-a28c-493e-a127-e07fddb11bb8)

 ![](https://firebasestorage.googleapis.com/v0/b/acousticatlasdata.appspot.com/o/users%2FySEj7xpMKRhIETEPrBBqSEveD9o2%2Fimages%2F5e961d14-67b2-4a1f-a9d8-8bef9b785bfa-BON_0321.JPG?alt=media&token=fec02ada-16ce-448c-872d-07b68649679f)

Victoria Cave

Waenhuiskrans Cave is a limestone cave, within the Waenhuiskrans Nature Reserve on the South African Cape coast. Due to ocean water sound levels inside the cave, this site does not have an impulse recording, only some ambient sounds to listen to.

 ![](https://firebasestorage.googleapis.com/v0/b/acousticatlasdata.appspot.com/o/users%2FySEj7xpMKRhIETEPrBBqSEveD9o2%2Fimages%2F85406685-369a-426f-af9d-cf17b5744550-IMG_3022.jpg?alt=media&token=b8d56568-a3a6-46e0-8eff-9719a3ddf232)

 ![](https://firebasestorage.googleapis.com/v0/b/acousticatlasdata.appspot.com/o/users%2FySEj7xpMKRhIETEPrBBqSEveD9o2%2Fimages%2F6f97b52a-ded6-4f74-b68e-46c18353b415-IMG_3019.jpg?alt=media&token=dd516696-e938-448d-8cbc-b466df770105)

Waenhuiskrans Cave

The name ‘Ripa Lupina’ is indicated in the drawing of Piperno’s book titled ‘De Nuce Maga Beneventana’ which describes this place as located in the valley of the river Sabato.  There exists a legend of witches that used to gather in the countryside and dance to the sound of beating drums under a magical walnut tree.  The natural acoustics from a very steep rock of about 50m would have amplified the sound of the drums.  Nearby are ruins of a defensive tower built by the Langobards and also in this area, a statue of an Apis bull, suggesting the existence of an Egyptian temple nearby.  The cliff is composed of a very steep rock At the foot of the cliff there is a side forest with a small stream collecting rainwater. 

Wolf Rock

York Cathedral was built between the 12th and 15th centuries on the foundations of the previous Norman church that was in turn constructed on the foundations of the original Roman fortress.

Its dimensions are approximately 27m high to the vaulted ceiling, 160m long and 76m wide.

It is constructed mostly of stone with extensive, large panels of stained glass windows.

York Minster Cathedral

Thingvellir is an Icelandic national park located about 50 kilometers from Reykjavik and Its surface area is 237 km2. Due to its cultural, historical, geological characteristics and its distinctive biodiversity, it represents one of the most significant places for Icelandic society. These characteristics led it to be proposed and declared a World Heritage Site in 2004. One of the most relevant events that occurred in Thingvellir is the establishment in 930 of the first Icelandic national parliament called “Althing” (Alþingi), becoming one of humanity’s first documented parliamentary institutions. According to most studies, a significant área of this assembly was located in a sector of the park called Lögberg (Law Rock), probably due to the layout of the natural amphitheater that this area has. In this place, the so-called Law-Speaker recited the laws, speeches were given on important topics and legal disputes were resolved. Some studies on Lögberg suggest the influence that the acoustics of this space could have on these meetings, however they do not delve much into this aspect. This article initially raises the question whether through an in-situ impulse response measurement it is possible to determine and quantify this influence. Subsequently, this investigation details the planning and field execution of these measurements. The results obtained, contained in an impulse response library, not only propose new research lines for future studies in the field of archaeoacoustics but also constitute an important safeguard of Iceland’s acoustic heritage.