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 that earned a B grade with a SoundScore of 3.7/5 in our lab testing, placing it in the top 45% of OTC devices. At $199, it represents an accessible entry point for those exploring hearing amplification. The Diamond X1's standout performance is in music streaming, scoring 4.1/5—a strong result that sits 2.18 points above the OTC category average. This makes it notably capable for users who prioritize audio entertainment through their hearing devices. Feedback handling is also excellent at 4.5/5, meaning users should experience minimal whistling during normal use. However, speech performance presents limitations. Speech in quiet scores a mixed 2.8/5, and speech in noise registers at 1.7/5. While both metrics technically sit above category averages (+0.03 and +0.22 points respectively), they remain low in absolute terms—important context for anyone prioritizing conversation clarity. Own-voice comfort is another weakness, scoring 1.7/5, which is 0.81 points below the category average and may affect how natural users sound to themselves. The Diamond X1 is best suited for budget-conscious consumers who value music streaming quality and aren't heavily reliant on challenging listening environments. Those who prioritize speech understanding in noise or natural own-voice perception may want to consider alternatives in this price range, such as the higher-scoring Elehear Beyond or Apple AirPods Pro 2.

Linner Mercury
The Linner Mercury is a budget OTC hearing aid priced at $387, earning a B grade with a SoundScore of 3.0/5 in our lab testing. This visible-in-ear style device ranks #60 of 65 in the OTC Hearing Aid category, positioning it in the lower tier of available options. In our standardized testing, the Mercury demonstrates excellent feedback handling at 4.7/5, scoring 0.16 points above the category average. This means users are unlikely to experience whistling or squealing during typical wear. However, the device shows limitations in other key areas. Speech in quiet scores 2.2/5, falling 0.62 points below the category average, while speech in noise performance is low at 1.0/5, sitting 0.48 points below average. Own-voice comfort is also low at 1.6/5, measuring 0.91 points below the category average. The most significant limitation is music streaming, which scores 0.0/5—a full 1.92 points below the category average. Users who plan to stream phone calls or music through their hearing aids should consider alternatives. At this price point, competitors like the Elehear Beyond and Apple AirPods Pro 2 offer substantially higher overall scores. The Linner Mercury may suit budget-conscious first-time users who prioritize stable, feedback-free wear over streaming capabilities or challenging listening environments. However, those seeking better speech clarity or music quality should explore other 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