Audiometry electricity calculator


measurement is usually performed using an "audiometer" by an "audiologist", although recently as audiologists are in short supply, more testing is being done by technicians. Hopefully, in the next 10 years or so, most of the testing may be done by the public as software is becoming available to test hearing on smartphones and similar devices. This will free up the audiologists to handle the difficult cases and give them more time to help people select hearing aids.

A very recent development is the capability to do screening audiometry on one’s own cellphone. Do it yourself, so to speak. This will probably drastically change how hearing testing is done as one can now test hearing right away. See this page for more. Pure tone audiometry Audiogram (figure 1) — this is a normal one.

pitches (250 Hz) to high pitches (8000 Hz). This is just a part of the entire human auditory range, which extends between 20 and 20,000 hz. Neverthless, most audiometers are designed so that they cannot go as low or high as most good stero systems. The audiometer that we use in our clinical practice is shown above.

The core method of pure tone audiometry is to present a series of tones in one ear, close to threshold (the loudness that the person can just barely detect), and keep dropping the intensity in 10 db steps until the person stops responding – -raising their hand or pushing a button. Then the person testing the hearing goes back up in 5 db steps until the person starts responding again. This is conventionally done at 6 octaves – -250, 500, 1000, 2000, 4000, and 8000. That’s most of it right there !

The threshold for each frequency, for each ear is plotted on a graph (see above). The right ear is usually plotted in RED, and as an ‘x’, and the left in Blue as a circle. There are special symbols for the conditions underwhich the hearing test is done (see below). Key used to interpret audiogram

Insert earphones are basically "earbuds", called by a different name. The insert earphones have the advantage that they block out environmental noise, and they also have less of a tendency to be heard by the other ear. Their main disadvantage is that they are a little trickier to use (one has to insert them properly), and also that they give wrong readings in persons who have perforations of their ear drums. Example normal audiogram (more examples are at the end)

WRS has some limitations – – most of us don’t communicate with monosyllabic speech, so a good score on the WRS may not necessarily correlated with good functional performance. Scores are also weighted towards perception of high frequency consonants. Poor performance overestimates everyday communication impairment for patients with high frequency hearing loss. WRS also underestimates hearing problems in noise. Complex speech tests

Practically, hearing measurements are meaningless unless your stimuli are calibrated. Every single part of the system that you use should be calibrated – -the electrical device that produces the sound, and the headphones or speakers that deliver the sound.

Practically, electrical devices (such as digital audiometers or CD players) will never drift in frequency or volume. Once their intensity is checked, formal electrical calibrations are more likely to cause trouble (i.e. noise in the calibration process) than be helpful.

On the other hand, mechanical devices (such as headphones, and insert headphones in particular) nearly always break down over time. They need to be checked everyday with a "sound check", and formally every 3 months. This can be very expensive if one asks one’s hearing equipment vendor to do this. So there is a conflict between the financial needs of one’s hearing equipment vendor and patient care.

(circles) although both ears are at least partially outside the normal range. Usually Red is used for the right, and Blue for the left. Red: Right — this makes it easy to remember. This is a sensorineural (neural more precisely) hearing loss. Example: Mild age-related sensory hearing loss

We think the most promising avenue is exploring more home testing — we think smartphones with appropriate software, could hugely improve accessibility of hearing testing. (Mahomed-Asmail et al, 2015). Smartphones "apps" are already pretty good. References: