No two ear canals are exactly alike. Even if two people were to have identical hearing tests and wear the exact same hearing aids, they likely still require different settings. So how do we know whether a hearing aid is actually delivering the right amount of amplification? Rather than relying solely on the hearing aid software's prediction, we objectively measure what the hearing aid is actually doing inside your ear using a process called Real Ear Measurements (REM). Widely regarded as the gold standard for hearing aid verification, REM helps ensure your hearing aids are programmed as accurately as possible before fine-tuning begins.

So What Exactly Are REMs?

As mentioned above, this is the process of measuring what's actually happening inside your ear. To measure this, we need to gently place a calibrated tiny microphone tube inside your ear canal, and then the hearing aid is worn over the top. There is a speaker placed in front of you during this process, and this will play calibrated speech sounds. We can then objectively measure the sound reaching your ear drum, and adjust the hearing aid programming live until this response matches your prescription. So instead of just estimating using only your hearing test results, we get an objective verification that also takes into account your ear anatomy.

Why Isn't the Manufacturer's "First Fit" Enough?

Based on your hearing test results, or 'audiogram', the hearing aid software will predict how much amplification you need at each frequency for each ear. However, every ear and ear canal is different. The shape and size of the ear and ear canal will determine how it collects and resonates sound, so you can imagine the acoustics for each individual ear varies. Therefore the manufacturer's first fit is a great starting point - but it's still a prediction, and finely tuned objective measurements are also required to ensure it works for your ears.

What Does REM Actually Measure?

1. Prescribed amplification: Is the hearing aid providing the amount of amplification that your prescription actually calls for?

2. Different pitches: Different frequencies require different amounts of amplification - again, dependent on your hearing loss and prescription.

3. Different input levels: Soft speech, normal conversational levels, loud sounds - these all need to be appropriate.

Why Does This Matter?

By objectively ensuring we actually have the correct amplification at each frequency reaching your ear drums:

• We expect improved speech clarity

• We expect better comfort

• There is a reduced risk of over-amplification

• We have great confidence that the hearing aids are performing as intended and the components (microphones, amplifier, speaker, etc) are working correctly

• It builds a stronger foundation for any required ongoing fine-tuning.

Does REM Guarantee Perfect Hearing?

No - it provides the best starting point.

• Further subjective fine-tuning based on real-world listening is still essential - it has to be totally personalised to your needs.

• Your brain will still need time to adapt. There are many new sounds and changes to the way that you would have grown accustomed to processing sounds. Our brains are very elastic, and this improves with continued and dedicated hearing aid use.

• Hearing rehabilitation is an ongoing process. Hearing aids are not a 'set and forget' type of device. This is why it's so important to ensure you are happy with your provider and working out what their aftercare is like. This doesn't mean the blanket "x amount of aftercare included", but also work out; How much time do they allow to spend with you in appointments? Are there limits to the number of appointments in that aftercare window? How easy is it to get in to see them?

Common Misconceptions

• "My hearing aids are expensive, so they must already be programmed perfectly"

Hearing aids - even the very expensive ones - are only as good as they've been programmed. The good news is, the very expensive ones do allow significantly more adjustments due to the increased amount of channels and features to make them work very well for a variety of environments automatically. Find an audiologist who is very confident in hearing aid programming.

• "If they sound comfortable, they must be correct"

Unfortunately, a comfortable sounding hearing aid does not necessarily mean that they are working optimally for your hearing needs. Comfort is part of the equation, yes - however, if they're comfortable and not providing you with the benefit you need, then what is the point?

• "Once they're fitted, they will never need adjusting"

This is one of the reasons I find people might start leaving their hearing aids in the drawer. I often hear "they used to be good, but now I don't notice any difference when I wear them". Hearing aids require ongoing review and optimisation. Our needs as humans change - whether that's a further change in hearing, acclimatising to the sound, a change in cognition/sound processing, or a change in social/lifestyle needs and environments. As our hearing and lifestyle needs change, the hearing aids need to be reviewed. Or, there may also be an issue with the hearing aids or your maintenance habits that can be picked up with routine checks by an audiologist.

How We Use REM at Solo Audiology and Hearing

REM is used for a number of different appointments, including but not limited to:

• Initial hearing aid fitting

• Hearing aid fitting follow-up if required

• Annual hearing aid reviews

• For those not totally happy with their hearing aids and seeking a second opinion

• Hearing aid troubleshooting

• Basically any time we need to know how the hearing aids are working - a REM is performed. This is all a standard part of our gold standard care.

Take Home Message

Hearing aid software provides an excellent starting point, but it cannot account for the unique acoustics of every single ear. Real Ear Measurements allow your audiologist to objectively verify what your hearing aids are actually delivering, providing the strongest possible foundation before ongoing fine-tuning and rehabilitation begins.

Written by Daniel Gerace, Clinical Audiologist and Owner of Solo Audiology and Hearing.