Infrasound can cause anxiety, a good source for this are wind turbines, but its naturally occurring in the wild anyway. Stags emit it to warn females and young of predator's without giving away the location of the stag as the sound hits the ground and spreads in all direction, like you see with bass frequencies. High pitched frequencies are very directional by contrast. Disney sound engineers discovered it in the US, when they slowed down the recording of an electrical device, all those in the sound lab went home not feeling very well at all, its a fascinating story of discovery. Diet can also cause anxiety, the renin angiotensin system can certainly increase anxiety, exercise will counter the effects of anxiety, which is less common today than 50 years ago.