How Do You Know You Need a Wireless Microphone?

In my last blog posting, I spoke about the technologies available to help you hear better in noise.  These included:

1. Directional Microphones
2. Fixed Gain Wireless Systems.
3. Dynamic Wireless Systems. 

But how do you know what technology you need?  This is a very important question that needs to be answered right away before you decide what kind of hearing devices you wish to purchase.  Let’s say you need Dynamic Wireless system in addition to hearing aids.  If you have sufficient financial resources at your disposal, you may wish to purchase a premium hearing and a wireless system.  This is the best of all worlds.  But if you have limited resources, you may wish to spend less money on your hearing aids in order to have enough money left over for a wireless system.

It is also important to know this in order to have realistic expectations about your hearing instruments.  If your hearing loss requires that you use a wireless microphone system in order to hear in a noisy environment, you can do countless hours of hearing aid fine tuning with your Hearing Care Professional and you are still not going to hear better in noise.  Its simple physics: a Dynamic Wireless microphone placed in close proximity to a speaker’s mouth will always outperform a microphone at the ear level.

Ideally you will have answered this question early in your hearing device selection process.  Here’s how this question can be answered:

1. Experience with Existing Hearing Devices.  If you already have hearing aids or a CI equipped with directional microphones and you are still struggling to hear better in a noisy environment, you will have answered your question about the need for a wireless system.
2. Experience with a Bluetooth Wireless Microphone.  As I mentioned in my previous blog posting, a Bluetooth Wireless Microphone will provide better performance than a directional microphone on your hearing devices.  But if you are still struggling with the Bluetooth mic, there are still significant improvements that can be obtained with a Dynamic Wireless System.  The microphones cut noise better, and the dynamic nature of the system will reduce the amount of noise your hearing aid or CI microphones will pick up.
3. Experience with a Fixed Gain Wireless System.  Similar to the above, if you already have tried a fixed gain system (Eg Phonak Campus, SmartLink SX, ZoomLink or EasyLink; Oticon Amigo, Comfort Audio Digisystem) and are still having trouble, then a Dynamic System will provide additional benefits particularly at noise levels at around 70 dB or greater.  This is about the level of a restaurant.
4. Audiogram Approach.  Most people with moderate-severe hearing loss or greater will require more than a directional microphone on the hearing instruments.
5. Direct Assessment of Hearing in Noise Abilities.  There are several tests that your Hearing Care Professional can perform to help determine right away what kind of technology you need.  The one I am most familiar with is the LiSN-S PGA test and as such I will highlight this test in the remainder of this blog posting.

LiSN-S PGA stands for Listening in Spatialized Noise.  Performed under headphones, a virtual 3D space is created with target sentences coming from the front and distracting sentences are coming from the left and the right.  The PGA stands Prescribed Gain Amplifier.  The stimuli are amplified according your hearing test results.  So it simulates the way you would hear in a noisy environment if you had hearing aids and an omni-directional microphone.

LiSN-S PGA accurately measures your ability to understand speech in noise as if you were wearing hearing instruments (amplification), and by your performance on LiSN-S PGA with normative data stored in the software, LiSN-S PGA predicts accurately the your performance in noisy situations compared to normal hearing listeners of the same age, and if the predicted performance is not good, LiSN-S PGA gives you clear, individual, technology recommendations how to improve speech understanding in noise. So based on your responses to the sentences, you get an evidence based recommendation.

The test takes about 5 minutes to perform.  You will hear noise first coming into both ears.  It will seem like the noise is coming from the sides.  Then you will hear a sentence that sounds like it is coming from in front of you.  Your task is simply to repeat back the sentence.  Your Hearing Care Professional simply needs to click on how many words you repeated correctly.  The computer will then automatically make the next sentence softer or louder depending on how well you did.  The test stops when the software has sufficient results to make a recommendation for you.

Here is what the recommendations screen looks like:

Personally I find it interesting that difficulty hearing in noise is one of the most common complaints that a person reports when getting a hearing test, yet most hearing care professionals never assess this.  Far too often we wait for a patient to fail with the hearing devices before we explore additional noise reduction technologies.  This is unacceptable.  Why frustrate people with hearing loss unnecessarily?

I know many Hearing Care Professionals are thinking, “Yes Peter, but many patients won’t use additional microphones, so I don’t bother introducing this technology”.  This thinking is also unacceptable.  You are making a pre-determination and denying people hearing loss technology that is critical to helping them function in our noisy world.   Our duty, as Hearing care Professionals is to help people with hearing loss make an informed decision.  Yes, some may reject such technologies initially, but it is still their right to be informed.

For more information about the LiSN-S PGA, click here.

For more information about the development of the LiSN-S PGA test click this link here.