Earlier quoted context omitted.
To me the first sample sounded like some subway passing by but when you're still far away yet. That said, after about 15 to 30s of attentive, continuous listening, it started making me increasingly uneasy, as I perceived the sound as being extremely oppressive and ominous, in a very chthonian way. I'm not going to try to listen to that any longer because I'm half sure that could almost turn into a panic attack of sor…
The concept of getting a panic attack in response to listening to some audio is completely foreign to me. Is it normal to have that reaction? It sure seems like it wouldn't be.
Constant, uniform stimuli for extended periods of time can produce weird effects on the mind. Think about stuff like sensory deprivation, staring at oneself in a mirror, anechoic chambers... And if someone can find a given sound soothing it's not out of this world to think that another sound could have the opposite effect.