Phonak’s new EON hearing aids run two AI systems on a chip built to sip power

Phonak’s new EON hearing aids run two AI systems on a chip built to sip power

The Prescription Still Wins: Why Sonova's AI Hearing Aids Keep Pulling Ahead While the OTC Revolution Stalls

In the style of IEEE Spectrum — feature analysis, August 2026

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Bottom Line Up Front (BLUF)

Four years after U.S. regulators tried to crack open the hearing-aid market with over-the-counter (OTC) devices — and two years after Apple turned a $249 pair of earbuds into an FDA-authorized hearing aid — the market's incumbents are not merely surviving. They are extending their technical lead. On 24 August 2026, Sonova's Phonak brand launched EON, a platform built around a custom low-power processor (HYPERSONIC) that runs two neural-network-driven audio systems in parallel while drawing roughly 37 percent less power than the prior generation. Meanwhile, OTC adoption has badly underperformed the hype: a 2025 survey found only about 5.7 percent of people who report hearing problems have adopted an OTC device, even as prescription sales keep growing and industry consolidation tightens. The engineering story and the market story point the same direction: real-time DNN speech processing, purpose-built silicon, and clinical fitting remain hard to replicate in a consumer earbud, and the channel that sells the best devices is consolidating rather than democratizing. The OTC category is real and growing in revenue, but as of 2026 it is a supplement to the prescription market, not the disruptor it was billed to be.

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A launch that reads like a spec sheet for the whole category

Phonak's EON is the third generation of the company's "Sphere" line, and its headline is a power-efficiency claim rather than a raw-performance one. The platform pairs a newly developed AI processor — Phonak calls it HYPERSONIC — with the company's ERA connectivity chip, keeping the dual-chip architecture introduced in the previous Infinio Sphere generation. One chip does the heavy neural-network math; the other handles the radios.

The two AI systems are worth distinguishing because they solve different problems. Spheric Speech Clarity 3.0 uses a deep neural network (DNN) to separate a talker's speech from background noise in real time — signal enhancement at the waveform level, not just gain shaping. AutoSense OS AI 8.0 is a scene classifier: it identifies the acoustic environment (quiet, speech-in-noise, music, and so on) and reconfigures which processing blocks are active, so the wearer doesn't manually switch programs walking from a restaurant into the street. Running both continuously is exactly the workload that punishes battery and thermal budgets in a device that has to disappear behind an ear.

The efficiency gain is the engineering payoff. Phonak states EON is 25 percent smaller and 20 percent lighter than the prior Sphere generation, with up to 38 hours of runtime per charge. That directly attacks the main criticism of the original Sphere: independent testers at HearAdvisor had measured it as the industry's best speech-in-noise performer, but it needed a bigger housing and more power than competing DNN designs. Because the smaller form factor depends on the new silicon and a more efficient algorithm, existing Infinio and Infinio Ultra devices can't be upgraded to EON in software alone — a reminder that in this category, the differentiator is still hardware.

Two other features round out the platform. WindBlock 2.0 is a dedicated subsystem that Phonak says cuts wind noise by up to 50 dB and can improve signal-to-noise ratio by up to 30 dB — a persistent complaint for outdoor wearers. And on connectivity, EON combines Bluetooth Classic, Phonak's proprietary Roger Direct wireless-microphone protocol, and Auracast broadcast audio, marketed under a "Made-For-All" banner meaning it pairs with essentially any Bluetooth device rather than a specific phone.

Auracast deserves more attention than its billing. It is part of the Bluetooth LE Audio specification and lets a venue broadcast audio to an unlimited number of receivers at once. A theater, museum, or airport gate can send its audio directly into a wearer's ears — the modern replacement for the telecoil-and-induction-loop systems installed in public buildings decades ago. Assistive listening has historically been worst in exactly those settings (a gate announcement, a guided tour), and a directly joinable broadcast is a genuine accessibility improvement, not a marketing flourish.

Phonak is shipping three configurations: the rechargeable Audéo EON Sphere, the Audéo EON R receiver-in-canal aid covering mild-to-profound loss, and CROS EON R for single-sided deafness, which routes sound from the unaidable ear to the better one. U.S. clinicians could order beginning 24 August 2026, with Germany, France, the U.K., Australia, and additional markets following in September. As is normal in a clinician-fitted, reimbursement-shaped category, Phonak did not publish pricing.

One caveat every rigorous reader should hold onto: the performance figures — "twice as likely to understand every word," the wind-noise numbers, the power savings — come from Sonova's own field-study evidence, not third-party benchmarks. They are plausible and consistent with the direction of the technology, but they are manufacturer claims.

Why this keeps happening to the market leader

Sonova is the world's largest hearing-aid manufacturer, parent to Phonak, Unitron, Advanced Bionics, and the AudioNova retail network. For the financial year ended 31 March 2026 it reported sales of about CHF 3.61 billion (~US$4.58 billion) from continuing operations, up 5.9 percent in local currencies, and said it continued to gain market share on the strength of its AI platforms. The company is guiding to 5–8 percent sales growth for FY 2026/27 and has flagged another AI platform for the second half of 2026 — EON is that platform.

Notably, Sonova is simplifying rather than diversifying. In March 2026 it announced plans to divest its Consumer Hearing business — the premium earbuds and headphones it sells under a licensed Sennheiser brand, acquired in 2022 to catch consumers early on their "hearing journey." That business only ever reached roughly 6 percent of group sales (about CHF 252.5 million), and management concluded it had different channels, cycles, and demand logic than medical hearing instruments. Under new CEO Eric Bernard, the message to investors is blunt: become the most profitable hearing-care company, and let someone else chase consumer audio. That is the opposite of the "earbuds will eat hearing aids" thesis.

The strategic logic is defensible on the engineering merits. The hard problem in this field is not amplification — it is intelligibility in noise, which is where DNN-based source separation running on power-constrained custom silicon actually moves the needle. That is a capital-intensive, IP-heavy competency, and it is precisely what Sonova has been compounding release over release.

The OTC promise — and the reality check

The policy story was supposed to end differently. The 2017 OTC Hearing Aid Act directed the FDA to create a device category that adults with perceived mild-to-moderate loss could buy without a prescription, exam, or professional fitting. The FDA finalized the rule in 2022 (devices reached shelves that October). The theory: strip out the gatekeeping and the four-figure price tags, and adoption would surge.

The strongest single data point in favor of that theory is Apple's. In September 2024 the FDA authorized, via its De Novo pathway, the first OTC hearing-aid software — Apple's Hearing Aid Feature (HAF), which turns AirPods Pro 2 (and later Pro 3) into a regulated hearing aid when paired with an iPhone or iPad. It runs an in-app pure-tone test, self-fits, and ships inside a $249 product tens of millions of people already own. In Apple's 118-subject clinical study, self-fitting produced perceived benefit comparable to professional fitting of the same device, with no adverse events. For a large slice of people with mild loss who would never walk into a clinic, that is a legitimate, stigma-free on-ramp — and arguably the most consequential thing to happen to hearing accessibility in a decade.

But the acoustic reality is more sobering, and it maps cleanly onto the prescription/OTC divide. Independent bench measurements published in 2025 found the AirPods Pro 2 amplify sensibly in the mid frequencies — with gains tracking NAL-NL2 targets — and that its Conversation Boost helps in moderate noise. The same analysis found the limits: weaker amplification at loud input levels, little fine-tuning, and less capable dynamic noise handling than dedicated hearing aids. In other words, the physics and the DSP still favor purpose-built devices for anything beyond mild loss or benign environments.

The adoption numbers tell the rest of the story:

• A 2025 survey found only ~5.7 percent of people reporting hearing difficulty had adopted an OTC device.
• Yet the same survey found roughly 70 percent of first-time buyers were choosing OTC — and overall adoption is rising. Both things are true: OTC is capturing new entrants while remaining a small share of the installed base.
• By units, OTC was about 1 percent of aids distributed through Hearing Industries Association members in early 2023, the last comparable tracking snapshot, and remains a small unit share.
• Return rates for some OTC models have been reported at 30 percent or higher — the fingerprint of self-fitting friction, mismatched expectations, and the absence of a professional to counsel through the awkward adaptation period.
• Prescription sales have shown no decline; the overall market keeps growing steadily. MarkeTrak's 2025 data put overall adoption around 39 percent, up from 23 percent in 1989 — progress, but slow, and not the step-change OTC was supposed to trigger.
• Estimates of U.S. OTC market value vary widely by definition (from roughly $272 million to the high-hundreds of millions in 2025), which itself signals an immature, loosely-tracked category.

Three structural reasons explain the gap. First, U.S. fee-for-service Medicare still doesn't cover hearing aids, so the affordability problem OTC was meant to solve is only partly addressed. Second, the FDA category covers only mild-to-moderate loss, leaving out many who most need help. Third — and most important for a market-structure analysis — the channel never really opened up.

The quiet consolidation: from product industry to supply industry

Here is where the "disruption" narrative inverts. Rather than fragmenting, the industry is integrating vertically. In March 2026, Italy's Amplifon — the world's largest hearing-care retailer — agreed to acquire the hearing business of GN (a "Big Five" manufacturer, maker of ReSound and the Jabra Enhance OTC line) for DKK 17.0 billion (~US$2.64 billion / €2.3 billion), in cash plus 56 million Amplifon shares, with closing targeted for end-2026 subject to antitrust approvals. A pure retailer is becoming a manufacturer-retailer; the factory and the fitting chair come under one roof.

Combined with Sonova's retreat to its core, the pattern is a market reorganizing around control of supply and distribution, not around consumer choice. Analysts have described it as a shift from a product industry toward a controlled supply industry. Five large manufacturers — Sonova, Demant, WS Audiology, GN, and Starkey — still shape pricing and access, frequently through retail and "hearing-benefit manager" arrangements that patients never see. That vertical integration, more than any technical barrier, is why the OTC rule hasn't reshuffled the market as intended.

On the legal front, the honest finding is that there is no blockbuster antitrust case currently targeting the hearing-aid oligopoly. The active legal exposure is regulatory: the Amplifon–GN merger must clear antitrust review in multiple jurisdictions before it closes, and it lands amid broader U.S. Department of Justice and Federal Trade Commission signaling that vertically integrated healthcare deals — where an owner can preference its own affiliates and foreclose rivals — warrant scrutiny. Recent U.S. vertical-merger challenges (AT&T/Time Warner, UnitedHealth/Change, Illumina/Grail, Tempur Sealy/Mattress Firm) show courts demanding hard evidence of foreclosure rather than predictive models, which cuts against easy intervention. The Amplifon deal has also drawn investor grumbling over price, but that is a shareholder-value dispute, not an antitrust one.

The science underneath the marketing

Both the incumbents and the OTC entrants lean on the same public-health tailwind: the link between untreated hearing loss and cognitive decline. The pivotal evidence is the ACHIEVE randomized controlled trial (The Lancet, July 2023), which followed 977 adults aged 70–84 with untreated hearing loss for three years, randomizing them to a hearing intervention or a health-education control.

ACHIEVE is routinely oversold, so precision matters. Its primary analysis across the full cohort found no significant reduction in three-year cognitive decline. The widely cited "48 percent slower decline" figure comes from a prespecified subgroup: participants recruited from the long-running ARIC cardiovascular study, who were older and at higher baseline risk. In the healthy community-recruited volunteers, the intervention showed no effect over three years. The defensible reading — and the one WHO and dementia researchers have adopted — is that treating hearing loss is a promising, low-risk target for people already at elevated risk of decline, not a proven memory pill for the general population. It is a real reason to treat hearing loss. It is not license for the more breathless claims that appear in product copy.

The takeaway for engineers and buyers

The specifications on both sides of this market are converging faster than the channels that sell them. A $249 earbud and a clinician-fitted aid now share vocabulary — DNN processing, self-calibration, Bluetooth LE Audio — and for mild loss in easy environments, the gap in outcomes is genuinely narrowing. But for the hard case that defines the category — understanding a specific voice in real background noise, all day, on a power budget that fits behind an ear — purpose-built silicon and professional fitting still win, and Sonova keeps widening that lead with each generation.

The OTC revolution did something valuable: it created a low-stigma, low-cost entry point that is pulling first-time users into hearing care. What it did not do is disrupt the incumbents or democratize the high end. As of 2026, the more accurate frame is a two-tier market — a growing consumer on-ramp feeding an increasingly consolidated, vertically integrated prescription industry — rather than the winner-take-all consumer disruption the 2022 rule was expected to unleash.

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Sources

Manufacturer and financial disclosures

1. Sonova International. "New EON hearing aid portfolio strengthens Phonak's leadership in speech understanding, scene intelligence and Made-For-All connectivity." 24 Aug 2026. https://www.sonova.com/new-eon-hearing-aid-portfolio-strengthens-phonaks-leadership-in-speech-understanding-scene-intelligence-and-made-for-all-connectivity/
2. GlobeNewswire (Sonova/Phonak press release). Same title, 24 Aug 2026. https://www.globenewswire.com/news-release/2026/08/24/3349447/0/en/new-eon-hearing-aid-portfolio-strengthens-phonak-s-leadership-in-speech-understanding-scene-intelligence-and-made-for-all-connectivity.html
3. Phonak. "Audéo EON Sphere — AI-Powered RIC Hearing Aid" (product page with field-study citations). https://www.phonak.com/en-int/hearing-devices/hearing-aids/audeo-eon-sphere
4. Sonova International. "Sonova delivers strong FY 2025/26 results with continued market outperformance and increased profitability." 18 May 2026. https://www.sonova.com/en/sonova-delivers-strong-fy-202526-results-continued-market-outperformance-and-increased
5. Sonova International. "Sonova HY 2025/26 Results." 14 Nov 2025. https://www.sonova.com/en/sonova-hy-202526-results-strong-sales-and-earnings-growth-local-currencies-outperforming-market
6. Sonova. Annual Report 2025/26 (full report PDF). https://www.sonova.com/sites/default/files/2026-05/01_Sonova_AR_25-26_Full_Report_en.pdf

Independent trade and technical coverage of EON

7.               HearingTracker (Karl Strom). "Phonak Eon Debuts Smaller Sphere, Auracast, and WindBlock." 24 Aug 2026. https://www.hearingtracker.com/news/phonak-eon-debuts-smaller-sphere-auracast-and-windblock

8.               Hearing Review. "Phonak Launches Eon Hearing Aids with New HyperSonic Chip and Auracast." 24 Aug 2026. https://hearingreview.com/hearing-products/hearing-aids/phonak-launches-eon-hearing-aids-with-new-hypersonic-chip-and-auracast

9.               HearingTracker. "Sonova Reports Strong FY 2025/26 Growth, Led by Infinio Platform." 18 May 2026. https://www.hearingtracker.com/news/sonova-reports-strong-fy-2025-26-growth-led-by-infinio-platform

OTC market performance and adoption

10.            The Capitol Forum. "Four Years After OTC Hearing Aid Rule, Competition in Hearing Aid Market Remains Limited Due to Deep Vertical Integration, Sources Say." 12 Jun 2026. https://thecapitolforum.com/four-years-after-otc-hearing-aid-rule-competition-in-hearing-aid-market-remains-limited/

11.            Suen, J. J., et al. "Are Over-the-Counter Hearing Aids Affordable, Accessible, and Satisfactory? Insights from MarkeTrak 25 Survey Data." (PMC), 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC12638185/

12.            AudiologyOnline. "20Q: Over-the-Counter Hearing Aids and Service Delivery Models — What We Know, and What Remains Unclear." https://www.audiologyonline.com/articles/20q-over-the-counter-hearing-29357

13.            Hearing Insider. "What Percentage of Hearing Aids Sold Are OTC in 2025?" 27 Aug 2025. https://hearinginsider.com/what-percentage-of-hearing-aids-sold-are-otc-in-2025

14.            Global Market Insights. "U.S. OTC Hearing Aids Market Size & Share Report." Feb 2026. https://www.gminsights.com/industry-analysis/us-otc-hearing-aids-market

Apple / consumer-earbud entry

15.            U.S. Food and Drug Administration. "FDA Authorizes First Over-the-Counter Hearing Aid Software." 12 Sep 2024. https://www.fda.gov/news-events/press-announcements/fda-authorizes-first-over-counter-hearing-aid-software

16.            Chong-White, N., Croteau, M., Kitterick, P., & Edwards, B. "Evaluating Apple AirPods Pro 2 Hearing Aid Software: Acoustic Measurements and Insights." Hearing Review, 10 Apr 2025. https://hearingreview.com/hearing-products/hearing-aids/otc/evaluating-apple-airpods-pro-2-hearing-aid-software-acoustic-measurements-and-insights

17.            National Hearing Institute. "Are AirPods Pro Hearing Aids? What the FDA Authorization Actually Means." Reviewed 13 May 2026. https://nationalhearinginstitute.org/articles/are-airpods-pro-hearing-aids/

Industry consolidation and vertical integration

18.            GN Store Nord A/S. "GN Store Nord A/S enters into agreement to sell its Hearing business to Amplifon S.p.A. for DKK 17.0 billion." 16 Mar 2026. https://www.gn.com/newsroom/announcement?id=3256006&lang=en&date=20260316

19.            HearingTracker. "Amplifon Strikes Deal to Buy GN Hearing in $2.64 B Transaction." 21 Mar 2026. https://www.hearingtracker.com/news/amplifon-strikes-deal-to-buy-gn-hearing-in-2-64-b-transaction

20.            Candesic. "Amplifon vertically integrates as Sonova refocuses core." 3 Apr 2026. https://candesic.com/article/amplifon-vertically-integrates-as-sonova-refocuses-core/

21.            Headphones.com. "Sennheiser's Consumer Division Is Being Sold. Again." 23 Mar 2026. https://headphones.com/blogs/features/sennheisers-consumer-division-is-being-sold-again

22.            Sidley Austin LLP. "DOJ Signals Increasing Scrutiny of Vertically Integrated Healthcare Companies." 4 Jun 2026. https://www.sidley.com/en/insights/newsupdates/2026/06/doj-signals-increasing-scrutiny-of-vertically-integrated-healthcare-companies

Hearing loss and cognition (ACHIEVE)

23.            Lin, F. R., et al. "Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE): a multicentre, randomised controlled trial." The Lancet 402(10404):786–797, 2023. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(23)01406-X/abstract

24.            ACHIEVE Study. "Key Findings." https://www.achievestudy.org/key-findings

25.            National Institute on Aging / Alzheimers.gov. "Hearing aids slow cognitive decline in people at high risk." https://www.alzheimers.gov/news/hearing-aids-slow-cognitive-decline-people-high-risk

Note on evidence: Phonak's performance figures for EON (speech-understanding, wind-noise reduction, and power savings) derive from Sonova's own field-study program rather than independent benchmarks. The one widely cited independent speech-in-noise ranking referenced here is from HearAdvisor/HearingTracker. Market-size figures vary substantially by source and definition and should be read as directional.