Coming This Week: The ReSound LiNX “Made For iPhone” Hearing Aid You Can Actually Use: UPDATED

The Hearing Blog has held off on publishing ratings on the ReSound LiNX “Made for iPhone” (MFi) hearing aid due to current drain issues, as unlike the #13-powered Starkey Halo, the original version was released only in their 312-powered x61 RIC platform.

October 1st Update: The LiNX, Enzo, and UP Smart (pediatric) brocuures and fitting guides are available for download at the bottom of this article. The UP Smart line is the slightly modified LiNX 67, 77, 88, and Enzo aids, with locking battery doors, LED status light, and more colors.

Like the older Verso, the LiNX draws about 2.0 — 2.4mA during normal use; but in our bench testing when receiving Bluetooth 4.0 Low Energy (“BLE”) digital audio the drain jumps to over 6mA, which in our engineering judgment is beyond the capability of the #312 cell due to short battery life and oxygen starvation, especially with Activair & Energizer an cells, including private label cells sold at Radio Shack, Costco & Sam’s. However, the drain figureswe measured are somewhat misleading, as due to the nature of the PWM audio output amplifier, the drain actually spikes above 10mA during loud speech peaks & in noise: This is something you can’t see on a digital drain meter, however those of us who have the older analog meters can watch this. Zinc-air batteries are actually mini fuel cells like those used on spacecraft, but with the oxygen supplied by the atmosphere; and it is these current peaks that cause temporary O2 exhaustion in the tiny #312 cell when the extra 3-4mA drain from UHF reception is in use. What’s more, this exhaustion problem has been exacerbated by the so-called “mercury-free” batteries, which have as much as 20% less energy capacity as well as a higher Thèvenin equivalent source impedance. The high drain coupled with the “new and weaker” cells is a problem our engineer colleagues at Starkey recognized early on, hence their offering their MFi Halo only in a #13 version.

ReSound LiNX technical specifications, current as of September 1st, 2014

ReSound LiNX technical specifications,
current as of September 1st, 2014
Click to enlarge in a new window

However, ReSound is finally releasing the LiNX in the #13 x77 thin tube BTE & x88 power BTE versions as well as the new “Enzo” #675 Big Boomer that’s on the same platform this coming week, and we await receiving them for bench and real-life testing; and we’ll report accordingly. Worth noting, however, is that ReSound has staunchly refused to release a #13 RIC aid, even though they have had this drain problem since their first-generation Alera was released in 2010.

We also need to remind our readers that out of the Big Six, only Starkey (and Audibel & NuEar), and ReSound (and Beltone & Cochlear) have true MFi hearing aids, i.e. ones that directly support Bluetooth 4.0 Low Energy (BLE). Phonak (and Unitron & Advanced Bionics), Siemens (and Rexton & Miracle Ear), Oticon (and Bernafon), and Widex each use their own proprietary 10.6 mHz digital transmission to get around the drain problem. This is OK for inter-ear coordination and control; but it falls apart because a streamer must be used as a relay between any audio signal and the hearing aids &/or CI’s. What’s more, the lack of a uniform 10.6mHz standard has pretty much reduced those users to using the lowest common denominator for public venue wireless transmission, namely troublesome and expensive baseband induction “hearing” loops via their T-coils.

ReSound Enzo datasheet, with the fitting range spliced in.Note the additional fitting range recommended by The Hearing Blog in the green shaded area.Click to enlarge in a new window

ReSound Enzo technical specifications, with the fitting range spliced in.
Note the additional fitting range recommended by The Hearing Blog in the green shaded area.
Click to enlarge in a new window

Brochure and guide downloads:

← FDA Finally Approves Use of ReSound Wireless Accessories With The Nucleus 6 CI Processor The Unethical Fake Hearing Aid "Research Study" Discount →

About the author

Dan Schwartz

Electrical Engineer, via Georgia Tech


  1. Caleb
    August 30, 2014 at 5:37 pm

    Finally an Enzo we can all afford! Does it come in Ferrari red?

  2. Dan Schwartz
    February 2, 2016 at 2:12 pm

    [Comment added by Dan]
    Hi Dan, I am really enjoying the wealth of information I have found in this, my first visit to your blog.

    I have been using Oticon Agil Pros (tried Alto 2 but didn’t see enough improvement to spend another $6500) but with the Agils over 5 years old and not that helpful to begin with, I am ready for something new, and very attracted by the Kirkland Signature 6.0, which I realize is the older Linx and has the 312 battery drain problem with Blue Tooth. My hearing loss is moderate to severe, but seemingly getting worse, and especially frustrating for speech in noisy environments, television/movies and music. I need CC even for television news/sports, though my real ear test shows the instruments are ‘hearing’ over 60 percent. I don’t know if I may have the cochlear dead zones you mention above.

    I really can’t spend the multiple thousands on new instruments unless they are absolutely going to provide a great improvement, so I’m tempted by the KS 6 devices. Their locked status isn’t ideal, but not an insurmountable obstacle. But I’m wondering if it’s likely Costco will use the Linx2 technology anytime soon for their next generation, in which case I could wait a few months. Any other suggestions or alternatives would be appreciated.

    Steve Klinger

  3. Patrick
    November 30, 2017 at 3:53 pm

    Hello Dan,

    My question is in regards to Made for iPhone technology. I have the Resound Linx2 and use them with my iPhone 7 Plus. The tech works really well, but of course sometimes the audio doesn’t immediately turn on at the start of a YouTube video – I have to sometimes spend a few moments clicking pause and then playing, etc. I assume Apple could continue to improve this with software updates? What type of hardware updates might be possible? I’m thinking Apple patented a certain Bluetooth technology level (4 something, not 5). Is that true? Could we see a Bluetooth 5 update of made for iPhone MFi?


Leave A Reply

Time limit is exhausted. Please reload CAPTCHA.

%d bloggers like this: