Compatible 3rd party LE Audio and Auracast devices - a technical deep dive

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#1

I’ve recently been diagnosed with moderate hearing loss and I’ve been wearing my first (trial-) hearing aids (Phonak) for just over a week now. I really like them, except for the limited battery life when streaming. Therefore I’m almost certainly going to get the Resound Nexia / Jabra Enhance 20 instead.

That’s obviously where LE Audio and Auracast comes in… After spending countless hours on this amazing forum, it seems that the technology is here, but there are very few 3rd-party devices, and compatibility is lacking.

Smartphone support is limited to recent Samsung models and people’s experiences have been mixed at best.

The only success story so far seems to be pairing the Nexia with Resound’s own Streamer+.

Streamer+ seems way overpriced, given that Moerlab offers an Auracast streamer for $50 and an identical model seems to be available on AliExpress for $30: https://www.aliexpress.com/item/1005005966279594.html

I have ordered the one on AliExpress, but given that the Moerlab one didn’t seem to work, I don’t expect it to work out of the box either.

I also just received an Intel AX210 Wifi/Bluetooth module, which supposedly supports LE Audio under Linux.

And lastly, I’m waiting for Nordic nRF52840 USB dongle to arrive. These are super cheap on AliExpress and apparently can easily be turned into a Bluetooth sniffer. Nordic’s web site is amazing, they seem to offer all their Documentation and Software for free. Also, Resound uses Nordic as their Bluetooth provider: GN Group unveils ‘world first’ Nordic-powered Bluetooth LE Audio and Auracast broadcast audio TV streamer - nordicsemi.com
Resound’s Streamer+ almost certainly based on the nRF5340 (nRF5340 - nordicsemi.com)

It will probably take at least another month for me to get the Nexia/Jabra, but I thought I’d start a thread for a technical deep dive already.

More in subsequent postings…

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#2

I should start by saying that while I’m an engineer and do firmware development for a living, Bluetooth is not my area of expertise. Please correct me if/when I’m wrong!

Let’s start with the Bluetooth standard and what’s likely required to connect to HAs using LE Audio or Auracast. Bluetooth specifies a range of services and profiles which build on each other to provide the desired functionality. This page shows what’s relevant for LE Audio, including links to the corresponding specifications.

Notice the ‘Use Case Specific Profiles’ HAP and HAS:

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These are the ‘Hearing Access Profile’ and ‘Hearing Access Service’, which are newly defined specifically for HAs.

So when the Moerlabs LE Audio streamer failed to pair with the Nexia HA (reported here: https://forum.hearingtracker.com/t/jabra-enhance-pro-20-now-supports-auracast/82691/15.), one possibility could be that Moerlabs doesn’t support the Hearing Access Profile (HAP).

So what does Moerlabs have to do to support HAP? Here is from the Bluetooth spec - the Moerlabs device would be a “Hearing Aid Unicast Client” (HAUC)

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The only mandatory requirements are support for the ‘BAP Unicast Client’ role (BAP = Basic Audio Profile), and the CISP set Coordinator (CISP = Coordinated Set Identification Profile).

But I don’t know enough about Bluetooth to know whether these are common features or new and onerous requirements…

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#3

I believe that user was using an iPhone, so Auracast was a non-starter.

#4

Hi wtolkein and welcome to the forum!

Here is my understanding of the situation and hopefully it will help you in your investigation. I’ve done some basic Bluetooth hacking and have a variety of sniffers, transmitters, receivers, etc. to mess around with that stuff and am very eager to see the new LE audio standards and support to begin rolling out to hearing aids and other devices. Hopefully this information will be helpful.

I don’t believe HAP/HAS is needed for 3rd party devices to work with hearing aids and the new LE Audio capabilities including the Auracast. HAP/HAS is optional and I think is focused more on interoperability between 3rd party devices and hearing aids across any manufacturer allowing remote control of programs, presets, volume, microphone gain, alerts, etc. Today, every manufacturer sells proprietary remotes or has proprietary software on the mobile devices to remotely control the hearing aids. In the future, the 3rd party device needs to be able to interact with the hearing aids to introduce new functionality, especially related to using the microphones in the hearing aids to transmit the users voice to interact with 3rd party devices. That level of integration controlling the gain levels of the hearing aid microphone without necessarily increasing the volume level of the receiver in the user’s ear. HAP/HAS provides remote control capability at that level.

I’m not very clear on the purpose of the unicast capabilities, but it seems like that is focused on extremely low latency communication such as broadcasting audio at a live event and having it synchronized with the person speaking into a microphone. That’s not much of an issue to deal with in a movie theater or TV since those already have latency correction capabilities, (lipsync) to keep things from looking off. Unicast looks more like extreme latency priority over audio quality.

If the Moerlabs device has base-level LE Audio, it should work just fine with a hearing aid claiming to support the same base-level of functionality without any need for HAP/HAS.

Capabilities like broadcast audio for Auracast have more dependencies above just the LE Audio streamer since you need to have the Auracast Assistant in the mix to direct the hearing aids to tune to the correct channel. It was looking like it would be a long road until everything would be in available and users had upgraded all of their devices, (mobile devices and hearing aids) with devices that support the LE Audio standards. There was some good news a few weeks ago when the Bluetooth SIG made a blog post with a new developed guide titled: Accelerating Market Adoption for Auracast™ Broadcast Audio. This guide describes how manufacturers and developers can work around an end user that may have new headphones or hearing aids that support Auracast, but they haven’t upgraded their mobile device. It’s pretty clever and should open the door to get things moving a little faster.

Blog Post:

Guide from the Bluetooth SIG:

Kind of a late-night brain dump on what I know about this stuff, but looking forward to hearing about what you discover and comparing notes.

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#5

Very interesting info. Even though I am a retired Audiologist and Hearing Instrument Specialist, I have been retired for over 20 years and Auracast is a fairly new technology, and totally new to me…

I purchased a MoerDuo transmitter hoping to cast my TV audio to my Jabra 20 Pro hearing aids. I use a Samsung S24+ android phone. Finding the Moer Auracast broadcast was easy with the Auracast assistant but… there was no audio broadcasted! The hearing aid does connect immediately to the MoerDuo but that’s it. No audio broadcast.

As I am currently visiting my son in Taiwan and MoerDuo is produced by a local Taiwanese company, I contacted them and they were very supportive. They sent me a replacement unit to make sure I did not get a bad one and they also loaned me a brand new HearClear Auracast earbuds set to try.

The new MoerDuo did not work any better than the first one. But the HearClear earbuds immediately connected and started receiving audio broadcasted by the MoerDuo connected to the audio of my laptop.

Sound quality was very good and latency was very low (around 45 msec I believe); there was absolutely no lip syncing problem in movies.

If only the Jabra Pro 20 could do the same thing! Their advertising of Auracast compatibility seems way over stated… In my experience, those hearing aids are not (yet) widely compatible with Auracast broadcasts.

When I compared the Auracast assistant page of the Jabra Enhance Pro BT LE and the one of the Moer HearClear, they are absolutely identical and behave the same way (likely a Samsung UI). However, the HearClear does receive broadcasted audio and the Jabra does not!

If someone has been able to connect the Jabra Pro 20 to an Auracast audio broadcast I would love to learn how to do it…

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#6

Thus far, I am only aware of them working with their own ReSound Streamer+ Auracast device.

#7

Thanks for your reply RSW.

So that would mean that the Jabra only has codec support for the Nordic nRF5340 and not the LC3… Unless I did not fully understand.

Jabra missed the boat on this one as the idea of using Auracast is not to establish a proprietary communication with only one system but to be compatible with all public Auracast broadcast. Sad!

Let’s hope they are going to be able to improve that in future firmware updates…

I am not holding my breath though as their support team does not seen to know much about the whole Auracast compatibility issue.

#8

I am hoping for a firmware update as well!

#9

:crossed_fingers:

I wish there was an email Adress to contact Jabra Support in writing to offer suggestions as calling their support line is a waste of time, you never talk to someone who really knows about Auracast, they only know about basic troubleshooting or how to pair a Bluetooth…

#10

Contact us | ReSound US has phone numbers and email addresses.

#11

If it only supports one brand of hardware it doesn’t support the standard. It has to support to LC3 to use the Auracast label.

It looks like you did the perfect test of Auracast on the Jabras (same transmitter, same phone as when you successfully used the buds) and it ain’t working. That’s disappointing.

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#12

Yes, you are right it is very disappointing and it is basically false advertising… I hope they have a way to fix that…

Update:

After a bit of research it may not be false advertising after all!

Apparently there are several implementations of the LC3 which are not compatible with each other! The most popular ones are the “mtk” scheme and the “Qualcomm” scheme.

From my investigation the MoerDuo seems to be using the mtk scheme. It is very possible that the Jabra 20 pro uses the Qualcomm instead, hence the incompatibility, even though both use the LC3 codec and are officially Auracast!

I have no way to find out what scheme the Jabra uses as getting technical info from them is harder to get than pulling a tooth…

If someone can provide tech info from Jabra that would be fantastic!

Jabra, are you monitoring this forum? :thinking:

#13

If two major SoC makers are putting out product that’s incompatible with the other’s product, the spec is in deep trouble. If you want to go the conspiracy route, maybe Resound has disabled access to all Auracast transmitters except its own? Naughty if true (which it probably isn’t).

I’d be surprised if Resound weren’t monitoring this forum. A whole department at Resound wouldn’t be doing its job if that were true. They’re just not interacting with it.

No-one here is a customer of Resound. We’re customers of audiologists who are customers of Resound/Demant/whomever. So when they see a bunch of posts from people who are having difficulty getting their expensive hearing aids to do what they expect them to do, Resound doesn’t have to do anything at all. Just wait for the audiologists to contact them piecemeal with their clients’ connection problems. And that’s low on the audiologists priority list because they’re audiologists, not communications specialists.

A central forum where Resound could advise of known issues with its products would be super nice. But then that would be admitting that there are known issues with its products, wouldn’t it.

There’s been a lot of time spent by people on this forum trying to get their Nexias to connect to third party transmitters. Multiply that by a thousand for people who don’t use the forum. Support the people who use your products, Resound.

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#14

Unfortunately, the staff on the online technical support does not seem to have the proper knowledge to answer highly technical questions like those regarding Auracast… So, sadly, I am not expecting much about the support we can get for the Auracast LC3 codec schemes…

PS: [Solved] I am new to this board and I don’t know how to quote the post I am replying to, at beginning of the reply… [Solved]

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#17

There are at least two ways, you can select the text you want to quote and the quote popup will show. Or you can click reply, and in the input box click leftmost icon [speech bubble] it will quote the post.

#18

Thanks Reginald, your help is much appreciated.

#20

→ highlight/mark the text you want to quote , then click the button Reply

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