There are syringes that come prefilled with saline used to flush IVs. Some people can taste it when it's injected, others can't. I'm one of those who can.

I can quickly learn to recognize specific people's footsteps, so I can hear who's approaching. Sometimes it doesn't even depend on what footwear the person is wearing.

Apparently I can hear high pitched sounds too. I've heard such sounds several times where people around me weren't able to hear it, and recently I could hear an ultrasound device too, which kinda make sense since they start at around 20 kHz.

Also, this isn't about sensing, but I can slow my heart rate temporarily simply by holding my breath.