Linner Mercury vs Otofonix Groove
Side-by-side HearAdvisor lab results with SoundGrades, expert pick badges, and the same visualizations we use in product reviews.

Linner Mercury
The Linner Mercury is a budget-priced OTC hearing aid that earns a B grade with a SoundScore of 3.1/5 in our lab testing. Priced at $387, it ranks #60 of 65 devices in the OTC Hearing Aid category, placing it in the top 91% of the category. In our testing, the Mercury shows a mixed performance profile. Its standout strength is excellent feedback handling at 4.7/5, which is 0.16 points above the category average—meaning users are unlikely to experience whistling or squealing during normal use. However, speech clarity metrics fall below category norms: speech in quiet scores 2.2/5 (0.62 points below average), and speech in noise scores a low 1.0/5 (0.48 points below average). Own-voice comfort also scores low at 1.6/5, sitting 0.91 points below the category average. Music streaming is a notable weakness, scoring 0.0/5—a full 1.92 points below the category average. Users who prioritize streaming audio from their phone should consider alternatives. The device uses a rechargeable battery and features a visible in-ear design with power dome coupling. At this price point, several competitors offer stronger overall performance. The Linner Mercury may appeal to budget-conscious consumers who prioritize feedback-free operation over speech clarity and streaming quality, but those seeking better speech understanding in challenging environments should explore higher-scoring options in this price range.

Otofonix Groove
The Otofonix Groove is a behind-the-ear prescription hearing aid priced at $795, earning a C grade with a SoundScore of 2.7/5 in our lab testing. This rechargeable BTE device ranks 36th out of 36 tested prescription hearing aids, placing it in the bottom tier of its category. In our testing, the Groove demonstrated one clear strength: excellent feedback handling at 5.0/5, scoring 0.29 points above the category average. The device remained stable during our standardized challenge motions with no audible feedback issues. However, speech performance was significantly limited, with both speech in quiet and speech in noise scoring 1.0/5—falling 2.32 and 0.96 points below their respective category averages. Music streaming quality scored 0.0/5, which is 2.64 points below the prescription category average. Own-voice comfort was also low at 0.4/5 in the tuned configuration, 2.35 points below average, suggesting notable occlusion-related concerns. The normalized Initial Score of 2.7/5 and Tuned Score of 2.6/5 indicate that professional fitting adjustments did not improve overall performance. Given its positioning at the bottom of the prescription hearing aid category and the availability of lower-priced alternatives that scored higher in our testing, the Otofonix Groove may be difficult to recommend for most users seeking balanced sound quality across listening situations.
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Performance metrics
Scale 1-5 (Tuned)
Lab metric by fit
Scale 1-5 (Tuned)
Speech level
Adjust input dB (Tuned)
Amplification (REIG)
Insertion gain at 65 dB (Tuned)
Audio scenes
Using MUSHRA scenes (Tuned)
Fitting configuration for tuned fit