Can I hear you now? Good!

Back in the early 80s we had an Apple ][ computer with the smallish green-and-black monitor (and a cassette tape drive, but I digress…). The monitor gave off a flat, high-pitched noise that was actually quite loud to me — not so loud that I didn’t use the computer 🙂 but loud enough to be a distinct sound among whatever else was going on in our basement family room.

The thing is, I _always knew when the monitor was on. I could be upstairs in our two-storey house, with my bedroom door and the door to the basement closed (old house = solid doors, not the wimpy hollow things they use these days) and hear it clearly. I would be in bed and my brother would come upstairs for the night, and I would look at him and say “You left the monitor on”.

“I did?”

It wasn’t too long before I realized that he couldn’t hear it. At all. I mean… how can he not hear that? Up the stairs, through a closed door, up another flight of stairs, and another closed door.

Computer monitors today are not nearly as noisy as they were in the days of black and white green, but I find that there are often other things that are similar. Can you hear the hard drive in an iPod when it’s not playing anything? Can you hear a PalmPilot while holding it normally in your hand? (Okay, that one takes a really quiet room, but I remember the first time I registered that that was what was making that sound!) A few years ago my wife bought one of those ultrasonic mosquito repellents. I can hear the danged thing when she turns it on! Sometimes I’m with my wife at some store, and I’ll say something about the music that is playing. She can’t hear it — it’s not actually playing in the room we’re in, it’s coming from the other end of the department store. I can clearly make out the melody.

My theory is that some people (such as myself) are simply more attuned to certain frequencies of sound.

The flipside of this is that I have in the last few years developed a notable difficulty distinguishing the sound of the human voice. If somebody is talking to me and there is any background noise, I frequently ask people to repeat themselves. It comes and goes, and because of this last detail, I am forced to alter my theory for this one….

Another thing that has been happening over time in the last few years is that my allergies have been changing. Where they used to hit me hardest in the upper front sinuses (causing sneezing, stuffed nose, and the like), they generally affect me further back and lower down in my head, resulting in post-nasal symptoms and fluid in my ears. Well, then. It’s not uncommon for me to yawn and suddenly have sound “snap into focus”. The odd bit about this is that while sound in general gets slightly muffled, it primarily affects my ability to hear the spoken voice. (An additional effect of this is that it’s not terribly unusual for me to get up in the morning and my balance to be all wonky for a few minutes.)

Short of a hearing aid, I suspect the best treatment is yet more (and better) antihistamines.

Dang it.

(As a side note, I am curious to track down the so-called “mosquito” sound that only teenagers are supposed to be able to hear. I bet I can hear it!) [Update: No, I can’t hear it.]

2 Responses to “Can I hear you now? Good!”

  1. Sam Says:

    Keep in mind that a HUGE part of hearing has nothing to do with the ear itself but the ways your brain interprets it. So while things like tinnitus and general hearing loss can be physiological problems in your hearing apparatus, the “selective hearing” you described is most certainly neurological in nature.

    You probably do have a slightly more sensitive ear than other people, but some of the situations you described aren’t so much cases of hearing things that are inaudible to others, but your brain “choosing” to hear what others don’t. Locations that people would call “quiet” are usually not quiet at all – there are all sorts of sounds all around you in your house or on a quiet street or even in the woods. It’s easy to appreciate the difference between the ambient noise levels at night and during the day, even though in both cases there aren’t actually any sounds you could pinpoint and name.

    The hum of the computer monitor or the mosquito repellent could certainly be in a frequency range that your brother or your wife can’t hear due to physiological reasons, but any music played back in a store is in the audible-to-all spectrum by design – your brain is simply better at picking up vague patterns from background noises. This seems like a plausible explanation to why you have difficulty focusing on something like a person’s voice – there’s something behind the ambient noises that’s competing for attention.

    Lots of people are incapable of having a telephone conversation if there’s a TV or a radio playing at moderate volume – I personally am not bothered by it at all. Given your ability to hear things others can’t, it’s quite possible that people often talk to you in an environment that has some sound equivalent to a TV or radio blaring in the background, and the auditory center of your brain zeroes in on that while you are consciously trying to focus on the person who’s talking to you, so you don’t actually consciously register the source of the distraction.

    This would also explain why it comes and goes – when it’s gone, there’s no distracting sounds in the ambient noise, and vice versa. Also, there’s a variety of factors that could affect the acuteness of your hearing at any time – alertness, tiredness, stress levels or even something more arbitrary like the light levels in your surroundings or the time of day.

    The “comes and goes” factor, on the other hand, seems to rule out any physiological defect in your ear, because something chronic and progressive wouldn’t go away, and acute temporary hearing loss due to excessively loud noises wouldn’t be likely to affect only a limited frequency range.

    Then again I’m not a doctor so I might be completely wrong. Just my interested-in-neurology layman’s two cents.

  2. Strider Says:

    Getting back to this (much later…), In recent years I’ve developed the habit of turning my head so that my ear is pointed at the person speaking to me. I think some people find this disconcerting, as by definition that means I am looking away from them.

    And Yes, I can distinctly hear them better when I do so.

    (Oh, and Sam — If you read this, thanks for the excellent info — layman or not.)

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