Phonak Sphere Infinio vs Sennheiser All-Day Clear Slim
Side-by-side HearAdvisor lab results with SoundGrades, expert pick badges, and the same visualizations we use in product reviews.
Choice

Phonak Sphere Infinio
The Phonak Sphere Infinio is a premium behind-the-ear prescription hearing aid released in 2024, priced at $4,898. In our lab testing, it earned an A grade with a SoundScore of 5.0/5, placing it at #2 among 39 prescription hearing aids tested—within the top 3% of its category. The standout performance comes in speech clarity. Speech in noise scores an excellent 4.7/5, a remarkable 2.59 points above the category average of 2.11/5. Speech in quiet also impresses at 4.5/5, sitting 1.07 points above average. For anyone who struggles to follow conversations in restaurants, gatherings, or busy environments, this device delivers measurably superior intelligibility compared to most alternatives we've tested. Music streaming quality is strong at 4.0/5, exceeding the category average by 1.24 points—a meaningful advantage for users who value audio fidelity when streaming from phones. However, own-voice comfort is mixed at 2.3/5, falling 0.40 points below the category average, which may affect how natural your own speech sounds. Feedback handling, while solid in absolute terms at 3.6/5, sits 1.12 points below the category average of 4.72/5. The Sphere Infinio is best suited for users prioritizing exceptional speech understanding, particularly in challenging noise environments, and who are willing to invest at the premium tier. Those especially sensitive to own-voice quality or requiring maximum feedback stability may want to compare alternatives like the similarly-priced Oticon Intent or the lower-priced Phonak Audéo EON Sphere.
Choice

Sennheiser All-Day Clear Slim
The Sennheiser All-Day Clear Slim is a premium OTC behind-the-ear hearing aid priced at $1,499, earning an A grade with a SoundScore of 4.1/5. This places it in the top 23% of OTC hearing aids tested in our lab, ranking #16 among 65 devices in its category. This device excels in areas that reflect Sennheiser's audio heritage. Music streaming quality is a standout strength, scoring 3.8/5—a solid result that's 1.88 points above the OTC category average. Feedback handling is excellent at 5.0/5, meaning users can expect stability without whistling during typical use. Speech in quiet environments also performs well at 3.6/5, sitting 0.85 points above average for the category. However, the All-Day Clear Slim shows limitations in other areas. Speech in noise scores 1.5/5, matching the category average but representing a low absolute score that may challenge users in noisy restaurants or group conversations. Own-voice comfort is below average at 1.9/5, which could affect how natural users sound to themselves during conversation. The All-Day Clear Slim is best suited for consumers who prioritize music streaming and media consumption alongside hearing support, and who spend more time in quieter environments. Those frequently navigating noisy social situations may want to compare against higher-ranked competitors in this price range, such as the Lucid Tala or Audicus Omni 2, which achieve stronger overall scores.
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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