#1

I am still trying to come up with a solution that will provide optimum speech-in-speech-noise intelligibility with my Audeo Q90’s. I have heard of NAL and NL-2 programming modes. I don’t really know what they are or how they differ from Phonak’s default programming mode (It has a name but I don’t remember what it is).
Can anyone explain to me what NAL and NL-2 are? Does anyone think it might be worth asking my audi to try programming using NAL or NL-2? Thank you.

#2

NAL stands for National Acoustic Laboratories. The NAL-NL2 is their latest prescription formula. It aims to make speech intelligible. The NAL is a research organization funded by the Australian federal government. Hearing aids can be fit with either the manufacturers first fit formulae or an independent standard like the NAL-NL2. In Australia the independent standard used is generally the NAL-NL2. A different one is used frequently in Europe. Many other countries also use the NAL standards as the NAL is held in high regard internationally. If you google them you can read all about them on their website.

Your audiologist should be able to compare the two prescriptions and show you how they differ for your hearing loss. If you are not happy with your results for speech then discuss this with the audiologist.

My personal experience of the NAL-NL2 targets has been good having had these used for my Linx 9s and Linx2 9s. My Phonaks were set up using audiogram direct and the Phonak first fit formula however this was compared to the NAL-NL2 targets and the high frequencies were lowered a little as Phonak tend to accentuate these a little more. Also make sure you have had real ear measurements done as these confirm that you are actually receiving the correct levels as per the prescription.

#3

NAL-NL2 is optimized for better comfort with “acceptable” clarity. The kicker is that each manufacturer implements NL2 differently. Some better than others. Generally, for Phonak devices, I recommend Phonak Adaptive Digital (Their proprietary formula), but if you are not getting good results, it never hurts to try NL2. Either way, I would suggest having your AuD do real ear measures and then speech mapping. Then you will see exactly why you are or are not getting the results you want.

Just an FYI for anybody else looking…

DSL is the major generic competitor to NAL. DSL is optimized for clarity at all costs. If you set your devices to speech mapped targets using DSL you will get the best clarity possible. BUT it will seem very loud and uncomfortable for most people.

Other rationales are…
Starkey uses Estat. It sucks. I almost always change Starkeys to NL2 to make them work well.
Oticon uses VAC. Its awesome. Still needs to be speech mapped sometimes, but overall, it provides the best speech clarity without getting insanely uncomfortable
Sonic Innovations uses Best Fit Fast. It sucks. Always underpowered. Switch to NL2.
Resound uses Audiogram+. Its ho hum. Not horrible, but not impressive either. But I usually get better results than changing to NL2.
Siemens uses Binaxfit/Miconfit/Connexfit… Not horrible, but not impressive either. I usually get better results with NL2, though.

There are others from other manufacturers. I could go on all day. Never hurts to try NL2 if you are not impressed with the manufacturer’s proprietary option.

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#4

Justin, thank you so much for your helpful response. When you talk about speech clarity, is that the same as speech intelligibility? From your response and from my previous experience, I would ask my audi to use DSL, REM and speech mapping. Maybe I could even bring in a female friend whom I have trouble understanding to do the speech mapping exercise. Then I could ask the audi to reduce the overall volume on the HA’s to a level I could tolerate. Then the audi could build a program using Phonak Target’s fancy features like AutoStereoZoom or ZoomControl to achieve the best possible speech-in-speech-noise performance using mic directionality.
Would that make sense in the real world of programming? In the past I have found that what makes sense to me as a patient is unachievable to an audi in the real world. The big question to me is: What setting algorithm or protocol (or whatever) would likely provide me the best speech intelligibility in a noisy bar/restaurant? Obviously the answer depends on my individual situation, but what would you try first? Thank you.

#5

speech clarity = speech intelligibility.

You could definitely bring your friend with you and you would be able to see EXACTLY why her voice is difficult for you.

Using special programs to achieve better performance in noise the way you are suggesting would probably be fruitless, but you could have a lot of fun trying and playing with it. If you were able, the best solution would be to use speech mapping to get intelligibility at optimal, then go set up a laptop with Target in a noisy place. Without adjusting the gain, only adjusting the directionality and the attack and release times and noise reduction parameters, you could hypothetically get a program set to your optimal comfort level. This is basically what Oticon is trying to do with their programming software.

The problem is your brain. What your optimal comfort level is right now may not be the optimal level for speech intelligibility in noise.

You have to think about the concept of scaffolding (psychological concept)… If you never push the capabilities of your auditory cortex, it will not expand those capabilities. Essentially you are relying on the technology to do all the cognitive work for you.

Think about doing work. You can move a pallet of bricks one brick at a time or you can use a forklift to move the whole pallet. If you rely on the forklift, that’s fine, but you’re likely to get fat and out of shape. If you try to rely on the directional mics/hardware to do all the work, your auditory cortex will get out of shape.

MRI studies prove this concept, by the way.

#6

Thank you for your helpful and interesting responses, Justin (and Psocoptera, too).

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