Phonak Sphere Infinio Ultra vs Signia Silk Charge&Go IX
Side-by-side HearAdvisor lab results with SoundGrades, expert pick badges, and the same visualizations we use in product reviews.
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.

Signia Silk Charge&Go IX
The Signia Silk Charge&Go IX is a premium-priced invisible-in-ear prescription hearing aid currently available at $3,298. In HearAdvisor's lab testing, it earned a B grade with a SoundScore of 3.7/5, ranking #30 of 36 prescription hearing aids tested. This device delivers excellent speech clarity in quiet environments, scoring 4.6/5—a full 1.30 points above the category average. Speech in noise performance is mixed at 2.2/5, though still slightly above average for the category. Feedback handling is strong at 4.3/5, providing reliable stability during daily wear. The Silk Charge&Go IX has notable limitations. Own-voice comfort scores low at 1.5/5, falling 1.25 points below the category average—a consideration for users sensitive to how their own voice sounds while wearing hearing aids. Most significantly, the device scored 0.0/5 for music streaming, meaning it lacks practical streaming capability from phones or other devices. At this price point, competitors like the Phonak Sphere Infinio (5.0/5), Oticon Intent (4.85/5), and Signia's own Active Pro IX (4.67/5) deliver substantially higher overall sound performance. The Silk Charge&Go IX may appeal to users who prioritize an invisible form factor and strong speech clarity in quiet settings, but those who value music streaming or own-voice comfort should explore alternatives.
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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