Cearvol Diamond X1 vs Linner Mercury
Side-by-side HearAdvisor lab results with SoundGrades, expert pick badges, and the same visualizations we use in product reviews.

Cearvol Diamond X1
The Cearvol Diamond X1 is a budget-priced OTC hearing aid available for $199, earning a B grade with a SoundScore of 3.7/5 in our lab testing. This visible-in-ear style device ranks #30 among 65 OTC hearing aids tested, placing it in the top 45% of its category. The Diamond X1 delivers a mixed performance profile with one notable strength: music streaming. With a score of 4.1/5, it performs 2.18 points above the category average—a substantial margin that makes it appealing for users who value audio entertainment through their hearing aids. Feedback handling is excellent at 4.5/5, providing stable performance during typical daily movements. Both iPhone and Android streaming are supported with rechargeable batteries for convenience. Speech performance presents a more modest picture. Speech in quiet scores 2.8/5, which is above the category average but only mixed in absolute terms. Speech in noise measures 1.7/5—above the category average of 1.48/5, though still low overall. Own-voice comfort is a weakness at 1.7/5, falling 0.81 points below the category average, which may cause your own voice to sound unnatural or boomy. The Diamond X1 is best suited for budget-conscious consumers who prioritize music and media streaming over maximum speech clarity. Those seeking stronger speech performance in challenging listening environments may want to consider higher-scoring alternatives in this price range, such as the Elehear Beyond or Apple AirPods Pro 2.

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.
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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)
Fitting configuration for tuned fit