GSI Introduces Good Question! Q&A Series


This year, GSI found an opportunity at AAA in Nashville to make our educational content more customized to the questions that GSI users had. Questions ranged from those about operation all the way to those about very specific tests. We invited convention-goers to step up to the mic and record their good questions. The questions were then answered by the GSI audiology team.

We took these recorded questions and answers to create Good Question!

Here are a few examples of the questions and answers that have come out of the Good Question video series.

Question: What is the difference between a 1.5 channel and the full 2 channel audiometer?


A 1.5 channel audiometer allows for the performing of diagnostic air conduction, bone conduction, and speech audiometry. Channel 1 is the primary channel for presenting the test stimuli, such as pure tones, monitored live voice, or recorded word lists. Channel 2 on this type of audiometer is the masking channel and is always routed to the non-test ear.

With a 2 channel audiometer, the channels are mirror images of each other. This means that any test stimuli may be presented from either channel. For example, you could present pure tones in channel 1 and speech stimuli in channel 2 at the same time. Or you could present pure tones in channel 2 with narrowband masking in channel 1.

A 2 channel audiometer provides complete flexibility, and for this reason is the audiometer of choice for most audiology practices.

Watch the video response below!


Question: Why are there 3 different probe tones for the GSI TympStar Pro?


The first probe tone that GSI TympStar Pro uses is the 226 Hz probe tone. This is the most common probe tone for patients whom are older than six months. It is very predictable and repeatable, and research shows this is the fastest way to diagnose a relatively normal middle ear system.

The second probe tone is the 1000 Hz probe tone, used primarily to diagnose infants whom are younger than six months. The reason we use that probe tone is because the infant ear is mass-dominated, so you may see erratic responses if you use the 226 Hz probe tone on this patient population. An infant may also have effusion in the ear and receive a completely normal tympanogram because of it. The 1000 Hz moves that probe tone away from the resonance frequency of the infant ear so that you can test with confidence and interpret those predictable responses just like the 226 Hz probe tone.

The third probe tone that the TympStar Pro uses is the 678 Hz probe tone. This is a more diagnostic probe tone for when you need to have a critical look at middle-ear components. If you have a patient with symptoms that don’t correlate with audiometric results, you can move to the 678 Hz probe tone, look at the susceptance and the conductance separately, and get a better idea of a disarticulation or fixation in the middle-ear system.

Watch the video response below!


To see the entire video series, which includes these questions and many others, visit any of our social media pages: Facebook, Twitter, Linkedin, or Youtube. We will be introducing two new videos a month through the end of 2018.

We want to continue the discussion with our users and anyone else who has a good question for GSI. If you have a good question you would like answered, and would like a chance to be featured in one of our “Good Question!” series videos, please email GSI at


The GSI Audiology Team