Linner Mars vs Sony CRE-C20
Side-by-side HearAdvisor lab results with SoundGrades, expert pick badges, and the same visualizations we use in product reviews.

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.

Sony CRE-C20
The Sony CRE-C20 is an invisible-in-ear OTC hearing aid priced at $999, earning a B grade with a SoundScore of 3.6/5 in our lab testing. This mid-priced device offers a discreet form factor with rechargeable batteries, positioning it in the upper tier of the OTC market. In our testing, the CRE-C20 demonstrates notable strengths in speech clarity. Speech in quiet scores 4.1/5—a strong result that sits 1.33 points above the OTC category average. Speech in noise performance reaches 2.7/5, which is 1.24 points above the category average, though only mixed in absolute terms. Own voice comfort scores 2.9/5, slightly above average for the category at +0.39 points. The device shows significant limitations in other areas. Music streaming scored 0.0/5, falling 1.92 points below the category average—this invisible-in-ear design does not support audio streaming functionality. Feedback handling registers at 3.9/5, which is solid in absolute terms, though 0.64 points below the category average of 4.54/5. The CRE-C20 demonstrates meaningful improvement with proper adjustment. The normalized Initial Score of 3.4/5 improves to 4.2/5 when tuned, suggesting users who invest time in optimization will see better results. Within its price range, alternatives like the Sony CRE-E10 (4.69/5) and Lexie B2 Plus (4.43/5) score higher overall. The CRE-C20 is best suited for users prioritizing discretion and speech clarity who don't need music streaming capabilities.
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