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 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.
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 3% of the 36 prescription hearing aids tested and ranking #2 in its category. This device delivers exceptional speech performance in our testing. Speech in noise scored an excellent 4.5/5, a remarkable 2.55 points above the category average of 1.96/5—one of the largest margins we've measured in this critical metric. Speech in quiet also performed strongly at 4.3/5, exceeding the category average by 1.00 point. These results suggest the Sphere Infinio Ultra prioritizes speech clarity across challenging listening environments. Music streaming quality is solid at 3.3/5, sitting 0.66 points above the category average. Own voice comfort scored 2.8/5, which is above the category average but remains mixed in absolute terms—listeners sensitive to occlusion may notice this limitation. Feedback handling measured 4.2/5, which is strong in absolute terms though 0.51 points below the category average of 4.71/5. The Sphere Infinio Ultra is best suited for users who prioritize speech understanding, particularly in noisy environments, and who are prepared to invest in premium technology. Those seeking the highest feedback stability or improved own-voice comfort may want to compare alternatives, though this device's speech performance stands out as a category leader.
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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