Phonak Audéo EON Sphere 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 Audéo EON Sphere
The Phonak Audéo EON Sphere is a premium behind-the-ear prescription hearing aid priced at $4,398. In HearAdvisor's lab testing, it earned a SoundScore of 5.0/5 and an A grade, placing it among the top performers in the prescription hearing aid category. Speech performance stands out as this device's greatest strength. Speech in noise scored an excellent 4.5/5, a full 2.53 points above the category average of 1.96/5—a substantial margin that makes this one of the strongest performers in challenging listening environments. Speech in quiet also performed well at 4.3/5, nearly a full point above the category average. These results suggest the Audéo EON Sphere may be particularly well-suited for users who frequently encounter noisy social settings or group conversations. Music streaming delivered a solid 3.7/5, more than a point above the category average of 2.64/5, indicating above-average audio fidelity for phone-streamed content. Own-voice comfort scored 2.8/5, which sits just above the category average but reflects mixed absolute performance—users sensitive to occlusion effects should discuss this with their hearing care provider. Feedback handling scored an excellent 4.6/5 in absolute terms, though it lands slightly below the category average of 4.71/5. The Audéo EON Sphere represents Phonak's latest premium technology and delivers strong results across most metrics in our standardized testing. It's best suited for users prioritizing speech clarity in difficult listening situations who are prepared for the premium price point.
Choice

Sennheiser All-Day Clear Slim
The Sennheiser All-Day Clear Slim is a premium behind-the-ear OTC hearing aid priced at $1,499, earning an A grade with a SoundScore of 4.1/5 in our lab testing. This places it in the top 23% of the OTC hearing aid category, ranking #16 among 65 tested devices. In our testing, the All-Day Clear Slim demonstrates notable strengths in music streaming, scoring 3.8/5—a solid result that sits 1.88 points above the category average. This makes it one of the stronger performers for users who prioritize audio quality when streaming from their phone. Feedback handling is excellent at 5.0/5, measuring 0.46 points above the category average, meaning users can expect stable performance without whistling during typical daily activities. Speech clarity in quiet environments is solid at 3.6/5, coming in 0.85 points above the category average. However, speech in noise performance is low at 1.5/5, matching the category average—a common limitation across OTC devices. Own-voice comfort scores 1.9/5, which is 0.61 points below the category average, suggesting some users may notice their own voice sounds different or hollow. The All-Day Clear Slim includes rechargeable batteries and supports streaming to both iPhone and Android devices with hands-free functionality. At its price point, alternatives like the Lucid Tala and Audicus Omni 2 offer higher overall scores, though the Sennheiser may appeal to those who value the brand's audio heritage and prioritize music streaming quality over speech-in-noise performance.
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