Linner Mars vs Phonak Sphere Infinio Ultra
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 that earns a B grade with a SoundScore of 3.1/5 in our lab testing. At $399, it falls in the lowest price tier for OTC devices, though its overall sound performance ranks #55 of 65 in the OTC Hearing Aid category. This device presents a stark contrast in performance across different listening situations. Music streaming is a genuine standout, scoring an excellent 4.6/5—well above the category average. Feedback handling also earns a perfect 5.0/5, meaning users shouldn't experience whistling or squealing issues. However, the Mars struggles significantly with its core hearing aid function: speech clarity. Speech in quiet scores just 1.9/5, and speech in noise drops to 1.0/5, both falling below category averages. Own-voice comfort is another weak point at 1.0/5, which is 1.51 points below the category average. Users may find their own voice sounds unnatural or boomy when wearing these devices. The tuned fit shows modest improvement over the initial fit (3.4/5 vs 3.1/5), primarily through better speech-in-quiet performance. The Linner Mars may appeal to budget-conscious consumers who prioritize music and media streaming over speech understanding. However, several competitors in the same price range—including the Elehear Beyond and Apple AirPods Pro 2—offer substantially better overall sound performance. Those seeking improved speech clarity should consider alternatives that score higher in that critical area.
Choice

Phonak Sphere Infinio Ultra
The Phonak Sphere Infinio Ultra is a premium behind-the-ear prescription hearing aid priced at $4,898. In HearAdvisor's lab testing, it earned an A grade with a SoundScore of 4.9/5, placing it in the top 5% of the 39 prescription hearing aids tested and ranking #3 in the category. This device demonstrates exceptional speech performance in our testing. Speech in noise scored 4.5/5—an excellent result that measures 2.40 points above the category average of 2.11/5. Speech in quiet also performed strongly at 4.3/5, which is 0.92 points above the category average. These results suggest the Sphere Infinio Ultra may particularly benefit users who frequently navigate challenging listening environments like restaurants or group conversations. Music streaming delivered a solid 3.3/5, measuring 0.54 points above category average. Own-voice comfort scored 2.8/5, which is above the category average by 0.10 points but remains mixed in absolute terms. Feedback handling measured 4.2/5—strong in absolute terms, though 0.52 points below the category average of 4.72/5. The Sphere Infinio Ultra is best suited for users seeking top-tier speech clarity who prioritize performance in noisy environments and are prepared to invest at the premium price tier. Those seeking similar sound quality at a lower price point may also consider the Phonak Sphere Infinio, which scored 4.98/5 in our testing.
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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