El volumen del sonido y las variaciones de la sensibilidad

“Un hombre que no había oído la explosión de una bomba cuando cayó al lado de su casa, por estar enfrascado en alguna observación con el microscopio, se quejaba, sin embargo, de que le hubiera molestado toda la noche el zumbido de un mosquito que rondaba su mosquitera. No se trata, por tanto, del volumen del sonido, sino de las variaciones de la sensibilidad y la mayor o menor concentración de la atención sobre las vibraciones transmitidas por el aire. (…) Los estímulos externos inducen reacciones en el cuerpo que varían en correlación con el estado de la sensibilidad interna. Un mayor o menor impacto externo no coincide forzosamente con una reacción de igual intensidad”.

Haruchika Noguchi

Silent but deadly [or why I can’t think clearly]

—So you think that music killed these people?
—Not music per se. Could you help me with this please, my dear?
—What about this? Would that work?
—Figaro? Perfect!
—We’ve known for some time that different sounds affect the brain in different ways.
—Look at my brain waves on the monitor.
—They’re smoothing out.
—Harmonic music reduces neural activity.
—Which is why we think more clearly when we listen to it, as opposed to this… Dissonance. Look… Look at my neurons.
—We get it, Walter. Can I turn this off now?
—Oh, sorry. You see, the point is this, that with this type of auditory phenomenon, taken to its ultrasonic extreme, can be fatal, and the way it affects the brain, it could well have induced some type of vegetative trance before death.
—Which would also explain the trauma to the inner ear.
—So we’re looking for some kind of deadly music box?
—No, it’s ultrasonic, so you wouldn’t be able to hear it, the frequency’s too high.
—Silent but deadly.

Fringe, episode 2 season 3.