Reference products and why people stop using them — chronic subjective tinnitus neuromodulation

1. Summary

The domain dossier's Section 5 flagged one gap above all others: no predicate-specific discontinuation or dropout figure, with a stated reason, had been located at abstract depth for the founding bimodal device, Lenire. This report retrieves full text for the three US-relevant predicate studies and finds retention data in all three, though none reports a stated per-patient reason for non-return, and all three carry a disclosed financial tie to the manufacturer, Neuromod Devices Ltd. [1][2][3]. Two independent, non-manufacturer-affiliated studies of the standard-of-care comparator (hearing aids used as tinnitus sound therapy) quantify device return rates directly, with stated reasons [4][5]. Separately, the FDA's own device classification registry shows the predicate does not compete alone: product code KLW ("Masker, Tinnitus," 21 CFR 874.3400) has at least 61 cleared 510(k)s on file, including two decided in 2026, and zero recalls in the last 20 years [6][7][8][9][10]. As of this report's access date, the predicate's own newer registered protocols still carry no posted results [11][12].

2. What Changed

_Baseline (v1). No prior version; this establishes the starting point for future diffs._

3. Details

The predicate's own attrition, at full-text depth

The domain dossier had read the predicate's pivotal trials at abstract depth only and found no per-arm dropout count. Full text of the settings-optimization RCT (TENT-A2, n=194 randomized, industry-sponsored by Neuromod Devices Ltd.) shows three participants withdrawn before device fitting — two did not attend the enrollment visit and one was withdrawn at that visit for an undisclosed medical condition — leaving 191 who completed fitting. Of those 191, 178 (93.2%) attended the 6-week interim visit, 173 (90.6%) attended the 12-week final visit, and 165 (86.4%) attended the first post-treatment follow-up. No reason is given in the results section for attrition during the treatment period itself [1] [single-source · manufacturer]. A separate, smaller real-world US chart review (n=220, Alaska Hearing & Tinnitus Center) reports: "At FU1, only two patients were lost to follow-up, and six more patients were lost to follow-up at FU2... resulting in a high retention rate of 96.4%," and notes that five of the six lost at the second follow-up had already shown improvement at the first — i.e. the paper frames this as loss to follow-up, not treatment discontinuation, and both authors disclose a Neuromod financial tie [2] [single-source · manufacturer].

A second, independent-cohort US chart review (2026)

A third, previously unretrieved study — a single-site chart review of 140 US patients fitted with Lenire at New York Hearing Doctors, published 2026 in the American Journal of Audiology — gives the most granular disposition data found in this domain to date. Of 140 patients fitted, 24 were lost to follow-up before the 6-week visit (116 attended, 82.9%); a further 30 were lost before the 12-week visit (89 of the 140, 63.6%, had paired data at both timepoints). The authors' own interpretation, tested directly: of 21 bothersome-tinnitus patients who attended the 6-week visit but not the 12-week visit, 57.1% had already met the minimal-clinically-important-difference threshold at 6 weeks, which the paper offers as evidence that "not attending the FU2 appointment does not necessarily indicate a negative treatment outcome." No field safety report, correction, removal, or recall was triggered by this cohort. One author (Hubert H. Lim) discloses a financial interest in and consulting relationship with Neuromod Devices Ltd., and Neuromod's internal funds supported study personnel and ethics fees; patients self-paid for the device and services [3] [single-source · manufacturer].

The broader FDA-cleared "tinnitus masker" device class

The dossier's Section 5 covered only the predicate (QVN) and three non-device standard-of-care categories (TRT, CBT, sound therapy in general). A distinct, older FDA product code exists for tinnitus-specific hardware: KLW, "Masker, Tinnitus," Class II, regulation 21 CFR 874.3400 [6]. A 510(k) search on this code returns at least 61 cleared devices dating back to at least 1996 (the connector's own window floor), including two decided in 2026: K260413, "Levo Gen 2 Tinnitus Therapy System" (Levo Medical Corporation, decided 2026-08-13) [7], and K260614, "Tinnitus Therapy" (Sivantos GmbH, decided 2026-06-10) [8], plus a 2023-era wave that includes "Peace N Quiet," "Tinearity G1," and hearing-aid-integrated tinnitus modules from GN Hearing and Starkey [9]. Zero device recalls were found for this product code in the last 20 years [10]. This is a much larger and more active reference-product landscape than the QVN classification the predicate alone occupies — QVN has had zero follower 510(k)s in 3.5 years per the domain dossier's own scan — though none of these KLW clearances is itself evidence that any specific masker device outperforms or is preferred over the predicate; the registry records existence and recency of clearance, nothing about outcomes.

Standard-of-care comparator: quantified hearing-aid discontinuation

The dossier's own gap list named the absence of any discontinuation-rate table for the hearing-aid/sound-generator comparator. Two literature searches this pass locate quantified figures. A retrospective chart review at a Korean university audiology clinic found that of 1,138 patients prescribed hearing aids, 81 (6.14%) returned them; "ineffectiveness of the device was the most frequent reason, accounting for 32.0% of returns," with financial difficulty cited more by younger adults and management difficulty more by elderly adults [4] [single-source]. A US, NIH-funded cohort study of 105 first-time hearing-aid adherents found that 21 (20%) returned their devices for credit within a one-month trial period, and that "the primary differences between these two groups of adherents were in the poorer aided outcomes obtained by those who returned their devices" [5] [single-source]. Neither study is affiliated with a hearing-aid manufacturer or with Neuromod; together they give this domain its first quantified, reasoned discontinuation figures for any comparator, though at different return-rate magnitudes (6.14% clinical-return vs. 20% trial-period-return) reflecting different study designs and populations.

Registry status, checked on this report's run date

Two of the predicate's newer registered protocols named in the domain dossier were re-checked directly against ClinicalTrials.gov on 2026-09-01: TENT-A3 (NCT05227365, actual enrollment 112, status COMPLETED) and a University of Minnesota customized-stimulus usability study (NCT07092033, actual enrollment 19, status COMPLETED). Both still carry hasResults=false — no change from the dossier's 2026-08-27 finding — meaning neither protocol's planned outcomes (THI/TFI change; compliance and satisfaction rate) have been posted as findings [11][12] [sponsor-reported].

4. Sources

[1] Conlon B, Hamilton C, Meade E, et al. "Different bimodal neuromodulation settings reduce tinnitus symptoms in a large randomized trial" — Scientific Reports (published 2022-06-30; accessed 2026-09-01). PMID 35773272; full text via PMC9246951 — https://pmc.ncbi.nlm.nih.gov/articles/PMC9246951/ [peer-reviewed] [2] McMahan EE, Lim HH. "Retrospective chart review demonstrating effectiveness of bimodal neuromodulation for tinnitus treatment in a clinical setting" — Communications Medicine (published 2025-04-28; accessed 2026-09-01). PMID 40295853; full text via PMC12037789 — https://pmc.ncbi.nlm.nih.gov/articles/PMC12037789/ [peer-reviewed] [3] Kasper CA, May JM, Crossland NE, Lim HH. "Bimodal Neuromodulation for Tinnitus in a Clinical Practice Setting: Clinically Significant Benefit for Patients With Moderate or Worse Symptoms" — American Journal of Audiology (published 2026, month not given in the PubMed record; accessed 2026-09-01). PMID 41528257; DOI 10.1044/2025_AJA-25-00090 — https://pubmed.ncbi.nlm.nih.gov/41528257/ [peer-reviewed] [4] "Clinical reasons for returning hearing aids" — Korean Journal of Audiology (published 2014-04-01; accessed 2026-09-01). PMID 24782945 — https://pubmed.ncbi.nlm.nih.gov/24782945/ [peer-reviewed] [5] "Differences Between Older Adults Who Do and Do Not Try Hearing Aids and Between Those Who Keep and Return the Devices" — Trends in Hearing (published 2021, month not given in the PubMed record; accessed 2026-09-01). PMID 34057370 — https://pubmed.ncbi.nlm.nih.gov/34057370/ [peer-reviewed] [6] openFDA device/classification, product_code=KLW — "Masker, Tinnitus," Class II, regulation 21 CFR 874.3400, review panel EN (current registry record; accessed 2026-09-01). 21 CFR 874.3400 — https://api.fda.gov/device/classification.json?search=product_code:KLW [federal-registry] [7] openFDA device/510k, k_number=K260413 — "Levo Gen 2 Tinnitus Therapy System" / Levo Medical Corporation, decided 2026-08-13, product_code=KLW under 21 CFR 874.3400 (accessed 2026-09-01). K260413 — https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm?ID=K260413 [federal-registry] [8] openFDA device/510k, k_number=K260614 — "Tinnitus Therapy" / Sivantos GmbH, decided 2026-06-10, product_code=KLW under 21 CFR 874.3400 (accessed 2026-09-01). K260614 — https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm?ID=K260614 [federal-registry] [9] openFDA device/510k search, product_code=KLW, decision_date 1996-09-08 to 2026-09-01 — 61 total matches (this repo's connector floor, truncated at 50 shown), including K233435 "Peace N Quiet" and K223694 "Tinearity G1," under 21 CFR 874.3400 (accessed 2026-09-01). 21 CFR 874.3400 — https://api.fda.gov/device/510k.json?search=product_code:KLW [federal-registry] [10] openFDA device/recall, product_code=KLW, event_date_initiated 2006-09-06 to 2026-09-01 — 0 records, under 21 CFR 874.3400 (accessed 2026-09-01). 21 CFR 874.3400 — https://api.fda.gov/device/recall.json?search=product_code:KLW [federal-registry] [11] ClinicalTrials.gov record NCT05227365 — "Treatment Evaluation of Neuromodulation for Tinnitus - Stage A3" (TENT-A3), Neuromod Devices Ltd. (record dated 2022-12-27; status COMPLETED; hasResults=false; accessed 2026-09-01). NCT05227365 — https://clinicaltrials.gov/study/NCT05227365 [trial-registry] [12] ClinicalTrials.gov record NCT07092033 — "Assessment of Customized Bimodal Stimulation for Tinnitus," University of Minnesota (record dated 2026-08-04; status COMPLETED; hasResults=false; accessed 2026-09-01). NCT07092033 — https://clinicaltrials.gov/study/NCT07092033 [trial-registry]

5. Sourcing & Gaps

Well established: Nothing in Section 3 rests on two independent, non-affiliated primary sources for the same specific quantity — every predicate-attrition figure comes from a single study, and the three predicate studies, while independently conducted cohorts, all share a disclosed Neuromod financial tie, so they are not treated as mutually corroborating even where their retention percentages point the same direction (roughly 82–96% retained through the final follow-up, none reporting a discontinuation reason). The zero-recall finding for product code KLW rests on a single federal registry query, which is the normal evidentiary shape for a registry fact rather than a gap.

Thin: All three predicate-attrition figures [1][2][3] are single-source and manufacturer-tied. Both hearing-aid discontinuation figures [4][5] are single-source, though neither is manufacturer-affiliated. The KLW clearance count [6][7][8][9] is a registry scan, not independently cross-checked against a second database.

Rescoped from class 3: None in this report. Every proposition is class 1 (a named registry record's status or count) or class 2 (a measured retention/return figure in a cited study), not a question about what a person would do.

Out of scope: MAUDE adverse-event narratives for Lenire or any KLW-coded device (no connector in this repo reads MAUDE — this is the subject of a separate, already-planned manifest row for this domain's pattern, per the potassium-monitoring-ckd sibling report's own precedent). HCPCS, payment-rate, and coverage-policy material (no local CMS cache; already flagged at the domain level). CPT descriptors (AMA-licensed). Non-US clearance or recall records (no connector in this repo queries a non-US source).

Not searched vs. not found: A per-patient stated reason for on-treatment attrition in TENT-A2 or the two chart reviews was searched for at full-text depth this pass and not found — a stronger negative than the domain dossier's original "not searched at full-text depth" note, but still an absence in what these three specific papers report, not proof no such analysis exists anywhere (e.g. in a supplemental file not retrieved here). Outcome data for any specific KLW-coded device beyond its clearance date was not searched — the 510(k) database records clearance, not performance, and no clinical-outcomes literature search was run per named KLW product. A head-to-head trial of the predicate against a hearing aid, TRT, or CBT arm was not searched again this pass; the domain dossier already recorded none located as of 2026-08-27.

[inference] The three predicate-linked retention figures (93.2%/90.6% at TENT-A2's two on-treatment visits; 96.4% in the Alaska chart review; 82.9%/63.6% in the New York chart review) are not the same measurement — different denominators, different visit schedules, and different definitions of "attended" — so reading them as a single converging "the predicate's attrition rate is low" claim would overstate what any one paper supports; this report presents them as three separate, individually-thin figures rather than combining them into a plain-stated line, which is my own judgment about how to apply the ≥2-independent-source rule here rather than something any of the three papers states.

6. Claim Candidates