 We're talking today a lot around the AirPods Pro, but in the wider context we're looking at them as an example of a change that's happening in the hearing technology landscape. And we're seeing a drive to improve access and affordability of hearing technologies with a lot of new products recently coming on the market. Now I'm particularly interested in apps and devices to help people hear and communicate better. When the new hearing features were introduced for the Apple AirPods Pro, I was really keen to explore them. So here I'm going to share some of the most interesting insights and learnings. So first up, what are the hearing features available in Apple AirPods Pro? How to set them up and personalize them as hearing devices? Were they going to look at the performance characteristics and go through some capabilities and limitations? So what are the hearing features available in AirPods Pro? Now most people who own AirPods Pro probably bought them as a nicely designed earphone with good quality audio, integrates well with their phone. They probably don't realize that they also contain some really useful hearing features. So here are some that I think are quite useful. Firstly, there's live listen. Now this has been around a while since 2014 and that's when you can use your iPhone as a remote microphone and you place it closer to the person speaking and it streams the amplified audio direct to your AirPods or your compatible hearing aids. And it's really useful in a noisy environment or if you're listening from across the room. Now the AirPods Pro also have three noise control modes. There's active noise cancellation. So apart from the obvious benefit where you can cancel out annoying sounds, you can also listen to let's for example your music or podcast in noisy environment without having to turn the volume level up really loud so you can maintain safer listening levels. The other really interesting one here is transparency mode and that's when you can let the outside sound in and be more aware of what's happening around you. The next one, background sounds. This has recently come in. You can listen and play calming sounds like a stream or the sound of rain and this can help alleviate tinnitus. And then the last two, what we're really interested in for this talk, headphone accommodations. You can customize your headphones to your hearing needs and individual preferences so you can hear sound clearer and also conversation boost. And this is to help hearing better and noise. So to delve into those last two a bit further, headphone accommodations. It was released in iOS 14 so like 2020 what it does is it amplifies the sounds based on the user's hearing needs. And there's a few different ways where you can set this up. You can use an audiogram which is going to give you the most personalized sound or you can do quick A, B listening comparisons. You can hear different versions of speech or music and choose the one you prefer and the system will choose the appropriate preset profile. So they have three preset profiles called balanced tone, vocal range or brightness and they can be applied at three different strengths. Now a really good benefit of the headphone accommodations is that there's no Bluetooth delay in the processed audio and if you've used some hearing amplification apps you may have noticed a delay or echo that affects the listening experience. With the AirPods Pro they do the audio processing in the H1 chip in the AirPods in the ear so you don't get that delay from relaying the audio from the phone to the earphone. And headphone accommodations can be applied to phone calls, media and to the sounds around you. That last one of course making AirPods more like hearables. Now the next one conversation boost this was released with iOS 15 so just towards the end of last year it aims to help improve communication and noisy environments. So we know that hearing impaired people have increased difficulty understanding speech and background noise. We can think of this as sort of like a directional mode. So in the Apple terms it uses computational audio and beamforming to focus on the person speaking in French. At the same time it's attenuation sounds around the listen to the background noise. So it's these two features headphone accommodations and conversation boost that we're most interested in when we're comparing the AirPods to hearing aids. So now we're familiar with the main hearing features how do we set them up and personalize AirPods Pro as hearing devices. Now it's not as easy as one might expect. It's actually these features are buried in layers of menus and set up can be a bit tricky. So this next part of the talk is a kind of tutorial but rather than rehash some of the instruction guide that are out there I'm going to focus specifically on how to tune headphone accommodations using an audio ground and also share some helpful tips. Okay so setting up headphone accommodations you go to the settings menu tap on accessibility then you want to scroll down and find the section about hearing. So here is hearing you tap on audio visual and then go to headphone accommodations. You want to switch headphone accommodations on and then go to custom audio setup. Now this recording will be available after the event so if you don't capture everything now you can check back later. So then we want to add a custom audio gram. So we go to add audio gram and there's a few different ways we can do this we can use the camera to take a photograph of the audio gram you can use a photo that you've already got stored or you can upload a file for example at PDF. I'm going to go through and take a photo with the camera because that's kind of fun. In this example I just pulled up an audio gram on my screen on my monitor but you could equally have one printed out on paper and the iPhone goes directly to camera mode you don't have to do anything it actually automatically finds that audio gram in the camera view and takes a photo so you don't even actually have to press that button down the bottom and it then displays what it thinks is the audio gram. Now I think that that looks pretty good I'm quite happy with that you can try and retake that photo if you want but we can move on and then it analyzes the audio gram and this part does require an internet connection. If you don't have internet available you can enter the values manually but with an audio an internet connection it'll go through and pull out the relevant hearing thresholds from that image. Now we see that it does pretty well but it's not perfect and we can scroll down if we want and look at some values that are missing and go in and enter those manually and correct any others that it may have not quite got right. Generally I find that if there are hearing thresholds that are the same in the left and the right ear it tends to miss one of them but you can go through and then confirm your data. Now one thing I've noticed is that the it's limited to the frequencies you see here so 125 hertz up to eight kilohertz in octave steps and there doesn't seem to be a way to and push any other frequencies that you might have. The next step is then to listen to audio samples with the recommended settings so that's using this audio gram that you've just put in and you can go through and listen to it switch between the custom the customized audio or the standard and choose the one you like. So if it's all working well the one that uses the audio gram should sound better to you. So that's the setting up with the head fund accommodations to the audio gram. What I also recommend is to do an ear tip fit and what this will do is just check that the ear tips you've got the right size they're sealing in the ear canal properly and that can really affect the sound quality it can affect the performance of the noise reduction and then just make things generally more comfortable. So to do this you go to settings and bluetooth you want to click on the little i icon next to the name of your AirPods Pro and the device list and it will bring up this menu and go to test ear tip fit. So this is the test you want to place the AirPods in your ear which they should be already if they're connected and when you press play it will play some music. Now you want it and it will come back with a result for each ear. Now in this case it's come back with a sort of a yellow result where it says adjust or try a different ear tip so you just want to try wiggling it around see if you can get a better fit and if that doesn't run the test again if that doesn't work you may want to switch to one of the different ear tip sizes. But with a good result it comes back green that's a good seal and the right size will not only be more comfortable it would reduce audio leaking out she'll get better low frequencies and reduce that ambient noise leaking in. The second tip I have is to create a hearing short catch in the control center. To do this go to settings and then control center. You want to look at that the hearing icon is not in the included controls so scroll down and find it and then press the little plus icon next to hearing. Now what that will do is when you go to control center it will put down the bottom this extra button with the ear on it so that's your hearing shortcut control and what that means is that you can then now do adjustments for headphone accommodations from the control center and you don't have to go back into all those accessibility setting menus. So when you press on that you can see all the AirPods options headphone accommodations you want to make sure transparency is in there so that they're going to work as hearing devices you can adjust the amplification so that's like a volume control the balance which is the balance between the left and the right audio channels scroll down a bit further you also have control over the tone so whether it's more low frequency darker or more high frequency which they call brighter and you can adjust the ambient noise reduction and turn conversation boost on or off. So these parameters can be easily adjusted by the user in the situation in the current situation however they feel they need extra boost or not. All right so how are we going out we're all set up what is the performance characteristics of AirPods Pro hearing features. So we performed electric acoustic and measurements in the lab both in quiet and in background noise. First we wanted to determine the amount of amplification and the frequency response provided by headphone accommodations and for these measurements we used an ear simulator which is widely used for standardized acoustic testing of headphones and hearing aids and we did measurements with the speech stimulus level at three levels so 50 dB SPL which is a soft speech level 65 an average level and an 80 dB SPL a loud level and these are the profiles the headphone accommodation gain for two preset profiles at moderate strength so for the balanced tone profile on the left we see that headphone accommodations gain at a level of 65 dB SPL gave a boost of about 12 dB between two and five kilohertz and we can see the compression there's more amplification for soft sounds than there is for the loud sounds on the right for the brightness preset there's more boost in the high frequencies with a 15 dB gain at four kilohertz at that 65 dB SPL input level. Now looking at how much gain control the user has with the quick adjustment settings with the amplification control they can slide it from zero to one hundred percent and this gives them a 12 dB range of gain adjustment cool and with the tone control this is a spectral tilt which pivots around about 1.5 kilohertz and going from zero percent which is the darker setting to a hundred percent brighter the user can increase amplification of the high frequencies by eight dB while simultaneously decreasing the low frequencies by up to four dB. Now if we want to look at how much gain can get a better fitting of sorry if we want to get a better understanding of what the fitting algorithm is in the AirPods Pro we can look at in pushing a custom audiogram and measuring the output levels so here are two custom audiograms we've looked at we've got one with a mild to moderate sloping loss from 20 to 50 dB HL and a flat 40 dB loss and we want to know how headphone accommodation gains compares to a typical hearing aid prescription so we can see here again the headphone accommodations gain but the solid lines at 50 65 and 80 dB SPL speech levels and we compare that to the null and our two prescriptions of the insertion gain which is shown by the dotted lines and we can see a really close match in the red which is the average speech levels but there's greater amplification with headphone accommodation so the yellow at loud speech levels and lower amplification with headphone accommodations at soft speech levels a similar result for the flat 40 dB HL audiogram greater amplification at loud levels and lower amplification at soft levels so we can expect there should be differences for the AirPods Pro compared to hearing aids that have been programmed to match null and our two targets and the audibility of soft sounds and for loudness comfort our next phase was to look at how AirPods Pro perform in background noise so showing here is one of our acoustic test rooms with a circular array of loud speakers we have a person sitting on that chair in the middle wearing AirPods Pro we put Pro Tube microphones in their ear to measure the level near the eardrum there's multi talker babble noise coming out from the speakers at a level of 65 dB SPL and we use a signal to noise ratio of minus 3 dB which is quite a challenging or common signal to noise ratio experienced for example in restaurants and then we use this phase inversion method to calculate the signal to noise ratio I won't go into too much detail but basically we play two successive recordings one with the phase of the speech signal converted and then when we subtract those signals we can extract the speech when we add them we can extract the noise and then calculate the signal to noise ratio so looking at the effect of these new features so there's conversation boost and ambient noise reduction we calculated the difference in the signal to noise ratio between using headphone accommodations with these features compared to what with these features turned on that is compared to when they're turned off and then to relate that SNR advantage to speech intelligibility we applied band important weights that were based on the speech intelligibility index so with this arrangement with noise coming from five speakers located to the side and the rear there was about a four and a half to five and a half dB advantage due to conversation boost being forming and this correlates to the directionality in hearing aids which increases speech intelligibility there was also around about a two dB advantage due to ambient noise reduction and noise reduction generally improves listening comfort so we saw there were slight differences between hearing loss profiles generally milder hearing losses with less amplification showed less SNR advantage due to conversation boost with a second more challenging arrangement with noise coming from all directions and out of all 16 speakers these measurements were repeated this time we've got a near normal audiogram in the hearing profile to match participants that we had in a study that was running in parallel with AirPods Pro and compared to the unaided condition we see the SII weighted SNR advantage overall of 5.3 dB but 3.2 when we're looking at just the conversation boost feature and this can be compared to hearing aids with conventional directional microphones that provide a three to six dB SNR improvement in diffuse noise right so just a quickly referencing to a study that was run by Rakeem Valdorama Venezuela where we were evaluating the benefits of AirPods Pro with normal hearing participants that had self-reported hearing and noise difficulties and just on one of the results from that study the speech and noise testing that was done with the same arrangement that we just showed that arrangement too with the noise diffuse around the listener the AirPods Pro provided a 12 percent increase in speech intelligibility compared to the unaided condition and on subjective ratings they said that with the AirPods Pro it was less mentally demanding it improved performance and required less effort so just the last section what are the capabilities and limitations of AirPods Pro I've mentioned quite a few of these already so for capabilities improved audibility of sound improved SNR and reduced background noise other things to consider the lower cost than hearing aids reduced stigma some people don't like the look of traditional hearing aids they have that active noise cancellation mode and another good thing is that there's frequent firmware updates so they're constantly getting new features without you needing to do anything extra on the limitation side we've seen that there's a limited control over the fitting parameters you don't have that flexibility to adjust the fitting like you do with a hearing aid fitting software the gain of the soft and the loud levels differs from some hearing aid prescriptions I didn't mention previously you can't set up the left and right is separately so the same profile actually gets used for both ears so that may be an issue if someone has an asymmetrical hearing loss they also lack some advanced features of hearing aids and they're more for situational use not for all day wear because of the battery life and some comfort issues so to close off as an overall summary the AirPods Pro now include features that give them hearing aid like functionality setting up the AirPods requires a number of steps and know how to get the most out of these devices and tune them to individual needs and I hope that the steps earlier can help with that our acoustic measures show that AirPods Pro provide frequency and level-dependent amplification and improve the SNR in noisy environments and while they do have limitations they may be a good low-cost situational use option for people with hearing difficulties that are not ready for hearing aids so that brings us to a close and thanks for listening I'd also like to thank my colleagues who have contributed to this work so Paul Heyman here, Joaquin Valdirama, Valence Swailer and Brent Edwards