I saw a tame shock video today, you know, one of those things where you’re looking at something and then a zombie or weird face appears out of nowhere. I knew it was coming and it wasn’t scary in any real way.
But it reminded me to ask about something that happens to me when I get a kind of jolt or surprise like that–particularly (though not necessarily) one where I see a face when I’m not expecting to: there’s a “thrud-duh-duh-duh-duh” deep in my ears, sometimes accompanied by my ears pulling back. It is entirely involuntary. It can be a video or something like turning around into someone’s face who I didn’t know was there.
Has anyone else noticed this about themselves, the thrumping or the ears going back? I wonder if it isn’t (at least the ears pulling back part) an atavistic response to fright, like when a cat or dog flattens their ears in anticipation of a threat.
Well, I don’t know about the ears pulling back. The description of the noise sounds a bit like the sound of my own pulse going through my ears, which could certainly become noticeable in a moment of fright. (Adrenalin getting the blood pumpin’ and all.)
The sympathetic discharge caused by a fright increases stroke volume (and often rate) of the heart.
You will feel this in your ears, in part because of their proximity to the cartotid pulsations.
Some people get a vagal discharge as well, which can slow the heart, increasing diastolic filling time and giving you a really big surge with each beat.
Of course it’s my heartbeat; I feel stupid for not realizing this at once. I guess I never supposed my heart could beat so quickly, vigorously, and for such a short period of time but the quality of the sound is the same as when I can hear my pulse in my ears after I’ve been, say, running down the block.
But no one else has felt their ears pull back as a reaction to fright?
I can’t say I remember experiencing it, but deliberately making a “startled face” for me involves tightening facial and scalp muscles including the ones that make my ears pull back.
The thumping you hear is more than six beats per second, yes? The human heart can’t beat that fast. Even if it did, it certainly won’t go from over 300 beats per minute (which happens, but only in the context of severe failure) to ‘startled’ speeds (200-ish bpm) instantly.
It’s your tensor tympani muscle. It’s a small muscle in the ear that dampens vibrations when engaged, protecting the ear structures from overly loud sound. Some people describe it as a ‘fluttering’ sound and sensation. I can engage it voluntarily (which is not terribly uncommon), and I can do so without engaging the muscles that pull my ears back, but it’s much easier to do both at once. It sounds like you’re doing that involuntarily as part of your startle reflex, which makes sense. For me at least, it also triggers when I yawn deeply.
