Linner Mercury vs Phonak Sphere Infinio
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.
Choice

Phonak Sphere Infinio
The Phonak Sphere Infinio is a premium prescription behind-the-ear hearing aid released in 2024, priced at $4,898. In HearAdvisor's lab testing, it achieved a SoundScore of 5.0/5 and an A grade, ranking #1 among 36 prescription hearing aids tested. This device delivers exceptional speech performance, particularly in challenging listening environments. Speech in noise scored an excellent 4.7/5, measuring 2.74 points above the category average—a substantial margin that sets it apart from competitors. Speech in quiet also performed strongly at 4.5/5, sitting 1.15 points above average. Music streaming earned a strong 4.0/5, exceeding the category average by 1.36 points. The Sphere Infinio does show some trade-offs. Feedback handling scored a solid 3.6/5 in absolute terms, though this falls 1.11 points below the category average of 4.71/5. Own-voice comfort scored a mixed 2.3/5, slightly below the category average. These are areas where some competing premium devices perform better. This hearing aid is best suited for those who prioritize speech clarity, especially in noisy environments like restaurants or social gatherings. The behind-the-ear style offers rechargeable batteries and streaming compatibility with both iPhone and Android devices. Among premium-priced competitors like the Oticon Intent (4.85/5) and Oticon Real (4.75/5), the Sphere Infinio leads in overall sound performance, earning HearAdvisor's Expert's Choice Award for 2024 and 2023.
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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