A Hearing Instrument Analyzer is used to measure and evaluate the performance of hearing instruments.
Every hearing instrument has a very specific characteristic regarding how much amplification it can provide, the maximum output level, battery consumption, etc. All this information can be found on the manufacturer's datasheets.
In order to check if a hearing instrument is alright, it is measured inside the hearing instrument analyzer and the results are compared with the manufacturer's data.
Of course background noise would make measurements impossible or at least distort the results considerably. Therefore it consists of a small anechoic or soundproof compartment which must be closed during the measurement.
An integrated loudspeaker produces a very specific signal which is picked up by the hearing instruments microphone. Placed inside the anechoic compartment is the hearing instrument connected to a coupler (most often with a size of 2cc).
The signal from the analyzer's loudspeaker is picked up by the hearing instrument's microphone and amplified. Inside the coupler is a microphone which measures the amplified sound produced by the hearing instrument.
Beside the purpose of quality check of hearing instruments, a Hearing Instrument Analyzer can be also used for hearing instrument fitting. However, there are certain limitations due to the fact that the actual ear differs significant in size and shape from the coupler used in HIAs. Therefore Real Ear Measurements are used to individualize hearing instrument fittings and make them more accurate.
