“I am sitting in a room,” Alvin Lucier’s classic work of sound art, will be performed by 90 artists in honor of his 90th birthday.
After 18,000 years of silence, an ancient musical instrument played its first notes. The last time anyone heard a sound from the conch shell trumpet, thick sheets of ice still covered most of Europe.
University of Toulouse archaeologist Carole Fritz and her colleagues recently recognized the shell as a musical instrument. To understand more about how ancient people crafted a trumpet from a 31cm (1 foot) long conch shell, the archaeologists used high-resolution CT scans to examine the shell’s inner structure: delicate-looking whorls of shell and open chambers, coiled around a central axis, or columella. A series of overlapping photographs and careful measurements became a full-color, 3D digital model of the shell, and image enhancement software helped reveal how Magdalenian people had decorated the instrument with red ocher dots.
And in a lab at the University of Toulouse, a horn player and musicology researcher became the first person in 18,000 years to play the conch shell. The musician blew into the broken tip, or apex, of the shell and vibrated his lips as if he were playing a trumpet or trombone. Very carefully, he coaxed three loud, clear, resonant notes from the ancient instrument:
A new review of the scientific literature confirms that anthropogenic noise is becoming unbearable for undersea life.
In the abyss, everyone can hear you scream.
MIT has developed a new navigation system designed for use underwater that could do for underwater wayfinding what GPS has done for travel on and above the surface. GPS doesn’t really penetrate underwater, because radio waves aren’t really water-friendly. It’s why you commonly see things like sonar employed on submarines, which emit sound waves and measure their reflection off of other underwater objects and surfaces. Typical sonar and other acoustic signalling methods are power-hungry, however – which is why MIT’s new battery-free system has so much potential.
GPS is also a relatively power-efficient technology, which is part of the reason it has done so much to transform how we get around, from in-car navigation to maps on smartphones. The limitations of current underwater navigation technology has meant that we typically need to use large, quick-to-deplete battery packs to power sound generation and transmission devices. MIT’s system would replace all that with a new type of battery-free acoustic navigation systems that sues signals already found in the environment rather than creating its own.
The system works by employing piezoelectric materials, which generate an electric charge when hit with mechanical stress, including the strain resulting from a sound wave impacting against them. Researchers created a way from these sensors to translate sound wave information into binary code, which they used to measure things like the temperature of the surrounding ocean or its salt content, but they theorized that it could also be used to figure out location information.
That’s more complicated than it might appear rat first, because sound reflects off of various surfaces underwater and travels back at often unpredictable angles. But the research team was actually able to account for this with an approach called ‘frequency hopping’ and collecting information across a range of different wavelentghts. This was effective in deep water, and now they’re working on making it more effective in the even noisier environment of shallow water.
Ultimately, the system and future versions that are based upon the same technology could enable future robotic submarine explorers to better map the ocean floor, and perform all kinds of automated monitoring and sub-sea navigation.
Scientists built a scale model of Stonehenge, the famous megalithic structure of stones in Wiltshire, England, and used it to recreate how sound would have been reflected off the surfaces of the stones. They found that the arrangement of the stones likely would have amplified speech and enhanced music but only if one was within the circle, according to a recent study in the Journal of Archaeological Science.
Dubbed “Stonehenge Lego,” the scale model is the work of acoustical engineer Trevor Cox of the University of Salford in England and several colleagues. (Fun fact: way back in 2007/2008, Cox conducted a yearlong study to identify the top 10 worst sounds. The sound of someone vomiting topped the list, followed by microphone feedback, wailing babies, and a train scraping along the track rails.) This latest paper builds on their preliminary findings last year. They’ve since been working on testing the acoustics of different configurations of the stones that would have existed at different times in the monument’s long history.
Recreating historical “soundscapes” is part of a relatively young field known as acoustic archaeology (or archaeoacoustics). For instance, researchers have sought to understand how acoustics may have influenced the outcome of key Civil War battles, like the Battle of Seven Pines on May 31, 1862. Another effect of interest to acoustic archaeologists is the chirping sound—reminiscent of the call of the quetzal, a brightly colored exotic bird native to the region—when you clap your hands at the bottom of one of the massive staircases of the Mayan Temple of Kukulkan at Chichen Itza in central Mexico.
Working from home often means having to cope with street noise and the clamor of children and pets. Here are some tips on how to quiet things down.
Bissera Pentcheva used virtual acoustics to bring Istanbul to California and reconstruct the sonic world of Byzantine cathedral music.