Siren are by far my favorite mythological creature. In traditional Greek mythology they are bird like creatures which live on an island. Their 'siren songs' cause sailors to become entranced and steer the boat towards the island whereupon they crash and became shipwrecked. In some myths the sailors would starve to death. In other myths they just simply drowned. According to other myths some sirens actually swooped up the drowning sailors dropped them onto the sharp rocks of the island and then feasted upon the sailors flesh.. Sounds fun right? In modern recreations sirens tend to resemble mermaids. Because being lured to your death by a mermaid is way better then being lured by a bird-woman right? Well no matter the type of siren you choose the physics behind your doom is still the same.
When the sirens sing they are creating sound waves. A sound wave is a mechanical wave and therefore requires a medium to pass through. Lucky for the sailors air and water can act as this medium. So even while drowning you can still appreciate the enchantingly deadly song of the sirens. But what makes a siren song deadly? Using the idea of resonance as evidence we can assume that its the frequency at which the sirens sing their songs which give it its deadly touch. Resonance occurs when one object emitting a sound wave with a specific frequency cause another object to vibrate with the same frequency. So here's my theory. Sirens sing at a particular natural frequency. This frequency then vibrates our eardrums. Our eardrums send this wave to our brains to interpret. Our brains do so by creating chemical paths in our brains. This is true of all sound. Now I'll attempt to explain they mythological part. The natural frequency at which the sirens sing is stored in a chemical path similar to the path where we store our natural euphoria's. Therefore when the sound is translated and stored in our brain it is confused with this natural drug and has a hypnotizing effect.
Cool side note: In physics the Greek symbol landau is used to represent wave length. here are some sirens names who have the landau symbol in them