What the NAL fitting prescription tells you about choosing hearing aids
I get asked this every week. “Al, which is better, Oticon, Phonak or Starkey?” Clients have usually been told one brand is the best in the world, and another clinic has told them it’s the other one.
Here’s my honest answer after more than 15 years in this industry. Most of the time, the brand isn’t the question. The technology level is. And the reason comes down to something most people have never heard of: the fitting prescription.
What is a fitting prescription?
When your hearing aids are programmed, your clinician doesn’t just guess how much volume you need. Your hearing test results go into a formula called a prescription. It works out exactly how much amplification you should get at each pitch, for soft, average and loud sounds. Think of it like a script for glasses. Different frames, same lenses.
The most widely used prescription in the world was built right here in Australia, by the National Acoustic Laboratories (NAL) in Sydney. NAL has been doing this research for more than 50 years, and its newest version, NAL-NL3, was developed from millions of real hearing aid fittings. (I’ve written a separate piece on what NAL-NL3 is and why it matters if you want the detail.)
That matters, because it means the same independent, evidence-based prescription sits inside the software of Oticon, Phonak, Starkey and the rest. The previous version, NAL-NL2, has been built into every major manufacturer’s fitting software for about 15 years. The new version, NAL-NL3, is being rolled out now. ReSound was first in March 2026, Phonak and Oticon have followed, and Starkey Australia has advised us directly that it’s coming in their next update. Depending on the brand, NAL-NL3 may only be available on newer models, so the generation of your hearing aid matters too. It’s a level playing field, and it’s there for a reason. It’s very, very good.
So what happens if you fit them all the same way?
Take a top-level Oticon, a top-level Phonak and a top-level Starkey. Give them the same receivers and the same domes or moulds. Program all three to the NAL prescription, then check each one in your ear with real ear measurement.
The amplification reaching your eardrum should be very close across all three. The core job of a hearing aid, making speech audible and comfortable for your hearing loss, is being done to the same script.
Where they differ is everything built on top of that: how each one handles background noise, wind, feedback, movement and streaming, plus the apps, accessories, rechargeable options and each maker’s sound “style”. Those features are real, and some of them are clever (I compared how three new flagships tackle background noise recently). But they sit on the foundation. They don’t replace it.
That’s backed by one of the best independent studies we have. Researchers at the University of Memphis gave older adults premium and basic hearing aids from different brands, all fitted properly with real ear measurement. In daily life, both levels gave people big improvements, and the improvements were essentially equal for most listening. That’s why I tell people a proper fitting matters more than the logo on the side.
Where the technology level does matter
This is where people get caught out. When you step down from a manufacturer’s top tier, you don’t get the same hearing aid for less money. You get the same shell with features switched off or turned down.
Oticon’s new Reveal is a good example. Every level looks the same from the outside. But going by the published specifications, Reveal 1 gives up to 12 dB of AI noise suppression, Reveal 2 steps down to 10 dB, and Reveal 3 drops to 8 dB. Reveal 3 also loses the 4D motion sensors, the feature that works out who you’re turning to talk to. Every manufacturer does some version of this.
Does that step down matter to you? It depends on your life. Research shows premium technology helps most for people who spend real time in noisy, demanding places: busy clubs, family gatherings, group conversations in cafés. If your days are mostly quiet, at home, one-on-one, watching TV, a mid-level device fitted properly may serve you just as well.
Buy the highest level you can reasonably afford
Dr Cliff Olson is a well-known and highly respected audiologist, founder of Applied Hearing Solutions in Phoenix, Arizona, and one of the most influential voices in our industry. He gives a piece of advice I’ve brought straight into my own practice: buy the highest level of technology you can reasonably afford.
If the premium level isn’t within reach, drop down to the level that is. There’s no shame in that, and a mid-level device fitted properly will still do a lot for you. But go in with your eyes open. Every time you drop a level, you potentially leave some performance on the table, usually in the hardest listening situations. That’s the trade-off, and you should make it knowingly rather than by accident.
Why we’re better off in Australia
Here’s where we have a real advantage over our colleagues in America. Over there, if money is tight, you’re often on your own. Here, we have the Australian Government’s Hearing Services Program.
If you’re an eligible pensioner or veteran, the program can give you fully subsidised hearing aids, meaning no cost to you for the devices. For people where finances are a significant issue, that’s a genuinely good outcome. And if you’d like more than the fully subsidised range offers, there’s a top-up option where you pay only the difference towards a higher level of technology.
Either way, the same rules apply. The device is fitted to the NAL prescription, and at AIM Hearing Bundaberg it’s verified in your ear, whether it’s fully subsidised or top of the range.
Compare level against level, not brand against brand
So when you’re weighing up hearing aids, stop asking “which brand?” and start asking two better questions.
First, is this the same technology level? Comparing a top-tier Phonak with a mid-tier Oticon tells you nothing about the brands. It only tells you about the tiers. Compare like with like.
Second, which level suits the way I actually live, and what can I reasonably afford? That’s a conversation, not a sales pitch. We go through where you struggle, how often you’re in noise, what you need the aids to do, and whether you’re eligible for government support.
The part nobody talks about: was it actually verified?
Here’s the catch. The NAL prescription only levels the playing field if it’s actually reaching your ear.
When a manufacturer’s software says “fitted to NAL”, it’s working from an average ear. Your ear canal isn’t average. Nobody’s is. Two people with the same hearing test can still need different final settings once the hearing aid is in their ear. A well-known study measured five manufacturers’ own NAL settings in real ears and found four of the five fell well short of the prescription for soft speech in the high pitches, which is exactly where the clarity of speech lives. A separate trial found people understood speech better when their aids were programmed to the NAL prescription using real ear measurement than with the manufacturer’s default first fit.
That’s why at AIM Hearing Bundaberg we perform real ear measurement on every single fitting. A tiny probe tube sits in your ear canal next to the hearing aid, and we measure what’s actually arriving at your eardrum. Then we adjust until it matches your prescription. It takes a little longer. It’s worth every minute. A hearing aid is only ever as good as its fitting.
The bottom line
A top-level hearing aid from any of the major manufacturers, fitted to the NAL prescription and verified in your ear, will give you a very similar foundation. Buy the highest level you can reasonably afford, compare like with like, check whether you’re eligible for the Hearing Services Program, and make sure whoever fits your hearing aids proves the fitting with real ear measurement.
If you’ve been quoted on hearing aids elsewhere and want a second opinion on whether the level suits you, bring the quote in. We’ll give you an honest answer. Already wearing hearing aids from another clinic? Here’s how transferring to AIM works.