Day 15

This is a particular cool sound example of throwing a rock onto a frozen lack. In an ice sheet high frequencies move fastest and so arrive first, followed by the slower, lower frequencies. Throw a rock onto a frozen lack and you get amazing chirps. You get a similar chirping sound if you clap your hands at the entrance of a long pipe. In that case it is called a Culvert Whistler. You can read more about this and other strange echoes in Sonic Wonderland / The Sound Book.

Day 16

What happens to the vocal anatomy when you sing a carol? Looking at an MRI of someone singing is spell bounding. Who knew the tongue was so large and flexible. Here is someone singing #DeckTheHalls in an MRI scanner. Warning, the singing is flat, but it can’t be easy to sing inside the machine.

Day 17

In 1650, Athanasius Kircher described an infamous piano where cats shrieked to create a tune. Now a missing page from Kircher’s manuscript Musurgia Universalis has been unearthed revealing a sketch for a #SantaClausPiano. Alex Wilson from #SalfordAcoustic has recreated the instrument.

Day 18

Bruno Fazenda from Salford Uni and collaborators, have investigated whether cave paintings were placed where there is interesting acoustics. Here is his fascinating paper on the subject or you can read the blog he wrote about the study. We sent trainee acoustican Santa to investigate further …

Day 19

Today’s #AcousticsAdvent was about a tiny whoopee cushion in a Christmas cracker, which stared in this film, alongside the World’s largest whoopee cushion. The large cushions were a prop for a science show, because they are driven by the same physics as the vocal chords. The rasping sound comes from a series of air puffs.

Day 20

Ghosts in the machine, as Christmas Images invaded my audio editor.
It’s like ‘[Equation]’ by AphexTwin! This is Granular Synth, using demo code that I made for students on Acoustical and Audio Engineering degree at Salford. But you could use freeware like Coagula to do something similar.

Day 21

What do your vocal chords look like when singing a carol? Amazing video of vocal folds opening and closing when singing. If you want to see how they get the camera in the throat this video from last year’s Royal Institution Christmas Lectures reveals all.

Day 22

An energy saving gadget for a tired Father Christmas. He only has to say one #Ho to get a #HoHoHoHoHoHoHoHo. Based on drawing by 17th century scholar Athanasius Kircher, who was obsessed with playing games with echoes.

Day 23

This Christmas angel has got some moves, but it’s disturbing when it hip thrusts. The video of the vibrating angel-shaped plate goes from low to high frequency and was made using a computer simulation.

Day 24

Listening out for Father Christmas in the 1930s? The Dutch personal parabola could amplify the sleigh bell jingle but became redundant once #ReindeerRadar was invented in the mid-1930s 🙂

Day 25

Coventry carol in venues with extreme reverberation. Including:

• #SalfordAcoustic Anechoic Chamber (reverberation time = 0)
• Hamilton Mausoleum, which used to hold the world record for longest echo (reverb time = 15 s)
• Vigeland Mausoleum Oslo, which has an extraordinarily long reverb considering its size
• The Inchindown Oil Depot, which holds the World Record for the Longest Echo (longest reverberation time of 75s).

I think the Hamilton Mausoleum is best for this carol. You can read more on why we like reverb in this New Scientist article. Many theories in the article, and one is that the emotional impact of music increases the more listeners are surrounded by it. You can read more about places with extreme reverberation in Chapter 1 of Sonic Wonderland / The Sound Book. The video made using virtual auralisation.

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