Cearvol Diamond X1 vs Linner Mars
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 Mars
The Linner Mars is a budget-priced OTC hearing aid released in 2023, earning a B grade with a SoundScore of 3.2/5 in our lab testing. At $399, it falls in the lower price tier of the OTC category but ranks #55 of 65 OTC devices tested, placing it in the bottom 17% of its category. This visible-in-ear device presents a mixed performance profile with notable strengths and significant weaknesses. Music streaming is a standout feature, scoring an excellent 4.6/5—a full 2.68 points above the category average. Feedback handling is also excellent at 5.0/5, meaning users can expect stable performance without whistling during normal use. However, speech clarity presents challenges. Speech in quiet scores a low 1.9/5, falling 0.85 points below the category average. Speech in noise performance is particularly limited at 1.0/5, sitting 0.46 points below average. Own-voice comfort also scores low at 1.0/5, which is 1.51 points below the category average—users may notice their own voice sounding unnatural or boomy. The Linner Mars may suit budget-conscious consumers who prioritize music and media streaming over speech understanding in challenging environments. However, buyers seeking better speech performance should consider alternatives like the Elehear Beyond or Apple AirPods Pro 2, which offer stronger overall sound scores in the same 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