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Product Comparison

Linner Mercury 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.

Uses Official HearAdvisor Lab Data
Linner Mercury Hero
LinnerSoundScore 3.0Grade B

Linner Mercury

The Linner Mercury is a budget OTC hearing aid priced at $387, earning a B grade with a SoundScore of 3.0/5 in our lab testing. This visible-in-ear style device ranks #60 of 65 in the OTC Hearing Aid category, positioning it in the lower tier of available options. In our standardized testing, the Mercury demonstrates excellent feedback handling at 4.7/5, scoring 0.16 points above the category average. This means users are unlikely to experience whistling or squealing during typical wear. However, the device shows limitations in other key areas. Speech in quiet scores 2.2/5, falling 0.62 points below the category average, while speech in noise performance is low at 1.0/5, sitting 0.48 points below average. Own-voice comfort is also low at 1.6/5, measuring 0.91 points below the category average. The most significant limitation is music streaming, which scores 0.0/5—a full 1.92 points below the category average. Users who plan to stream phone calls or music through their hearing aids should consider alternatives. At this price point, competitors like the Elehear Beyond and Apple AirPods Pro 2 offer substantially higher overall scores. The Linner Mercury may suit budget-conscious first-time users who prioritize stable, feedback-free wear over streaming capabilities or challenging listening environments. However, those seeking better speech clarity or music quality should explore other options in this price range.

Expert Choice
Expert
Choice
Hero Image
PhonakSoundScore 4.9Grade A

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 in quietNew
Linner Mercury2.2
Phonak Sphere Infinio Ultra4.3
Speech in noiseNew
Linner Mercury1.0
Phonak Sphere Infinio Ultra4.5
Own voice
Linner Mercury1.6
Phonak Sphere Infinio Ultra2.8
Feedback handling
Linner Mercury4.7
Phonak Sphere Infinio Ultra4.2
Music streaming
Linner Mercury0.0
Phonak Sphere Infinio Ultra3.3
Overall fit score
Linner Mercury3.0
Phonak Sphere Infinio Ultra5.2

Speech level

Adjust input dB (Tuned)

Amplification (REIG)

Insertion gain at 65 dB (Tuned)

Fitting configuration for tuned fit

Linner MercuryPhonak Sphere Infinio Ultra
Ear CouplingPower Dome
Ear CouplingEasyGuard Vented
Receiver–
ReceiverMedium-power
Fitting Formula–
Fitting FormulaAdaptive Phonak Digital 3.0 (Manufacturer proprietary targets)
Listening Program–
Listening ProgramAutoSense OS (Automatic)
Volume Setting–
Volume SettingAdjusted to match NAL-NL2 targets at 55, 65, and 75 dB SPL
Software Version–
Software VersionV1.1.11.0
Tuning Adjustments–
Tuning AdjustmentsProgrammed to N3 audiogram, Feedback calibrated, Long-Term Experienced User, Other settings at manufacturer defaults