Welcome to the second episode of Brain Music.

Part 1: Sonic island hopping in a forest of LEDs and lasers, in a church in Copenhagen during the Culture Night of 2016 – interview and live concert with Jesper Skovgaard aka. Noosphere.

Part 2: Physicality of sound #1 – Signal Transduction
In order for you to hear my voice, multiple transductions and conversions of the signal have to take place.

Noosphere – hvem er det?
Ordet ‘Noosphere’ omfatter sfæren for det menneskelig sind og er et musikalsk projekt, der sigter mod at skabe musikalske rejser der giver mulighed for – og driver – udforskning af de indre verdener af tanker, følelser og andre hjernevridende abstraktioner af det menneskelige sind. Bag Noosphere er den danske elektroniske musiker og lydteknolog Jesper Skovgaard, som undersøger de fascinerende verdener af cinematisk elektronisk musik for at fremkalde indre billeder i lytterens sind.

How can you hear me?
Thought –> vocal chords of my voice –> vibrations in the air –> membrane of the studio microphone –>
Analog to digital, AD signal conversion –> data stream of 10101001s –> your listening device –> digital to analog, DA –> membrane of your speaker (reversed-ish microphone) –> vibrations in air –> ear drum –> signal transduction –> neuronal symphony, plethora of firing –> smiley face

Three parts of the ear – outer, middle, inner

Outer ear
Pinna – flap of cartilage, funnels sound, why is it so weirdly shaped compared to a rabbit’s ear? Important for localization!

Auditory canal – external auditory meatus (leading to interior of our body), short crooked tube, resonant properties, channels vibrations to the eardrum.

Middle ear
Tympanic membrane (eardrum), thin, taut (stretched), easily punctured, vibrates in response to pressure changes in ear canal, connected to throat via Eustachian tube, swallowing or yawning opens this.

Ossicles (malleus, incus, stapes – hammer, ambolt, stigbøgle)
Transmit pressure changes from air-filled middle ear to fluid filled cochlea. Lever system concentrates pressure changes at eardrum (large, weak) onto smaller area of the oval window of the cochlea (small, strong). Roughly 20 – 30 times pressure amplification. Push and pulls on the oval window, transferring the vibrations from air to liquid.

Inner ear
Tune in next week for the next episode where we go deeper into how our mind transduces physical energy in the air into neuronal firing.

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