Friday, February 18, 2011

Tymponometers...tymp what?

Okay, one more gadget related to hearing screenings: the tympanometer. Like the otoscope, this device does not test what a client can hear or not hear, but helps evaluate the health of the middle ear. A tympanometer increases and decreases the pressure in the ear canal and charts the response of the eardrum (tympanic membrane) to the changes in pressure. Ideally, the eardrum should flex, indicating that is responds correctly when it comes into contact with sound waves. This produces a chart, known as a Type A tympanogram, that looks like this:

When the eardrum does not work properly, you will get charts that look like the following:
The first atypical graph is called a Type B tympanogram. This type indicates little or no flexibility of the eardrum, which could be attributed to fluid/infection located behind the eardrum, or even a hole in the eardrum. The second atypical graph is a Type C tympanogram. This type has a peak, indicating flexibility of the eardrum, but the peak is shifted to the left (in the negative numbers), indicating an abnormal amount of negative pressure in the ear canal. This can be attributed to congestion of the sinuses, often due to colds or allergies. (All the picture graphs were taken from Wikipedia)

Tympanometers come in a few different varieties. I, personally, have used two different kinds. The first kind I used is a little more complicated and, although portable, is more of a hassle to move around, as it must be plugged into an outlet. A picture, taken from, is shown below.This shows a person holding the probe, which is the part you stick into the ear canal. You can also see that it prints out a paper copy of the graph (described and shown above).
The second variety that I have used before is much smaller and is shaped more like a gun (It looks a lot like an otoscope) which sits on a charger when not in use. It is much easier to stick in the ear, and gives you a picture of the graph on a small screen. If you wanted to print it out, the charger has a printer built into it. A picture, from, is shown below.
This concludes my segment on gadgets used in hearing screenings--next I will be discussing some very interesting technologies used as alternatives to oral communication. 


  1. Michelle, this is very interesting. You mentioned that a problematic chart could indicate a hole in the eardrum? What causes this? Is it genetic and is there an operation that could fix this?
    It is so neat that the science seems to remain more or less the same for audiology/speech pathology instruments, while the gadgets themselves adapt/progress to sleeker, more user-friendly models.

  2. Great question Liz! I'll make sure to post on this soon :)