Phonak Sphere Infinio Ultra vs Signia Styletto C&G 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 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.
Choice

Signia Styletto C&G IX
The Signia Styletto C&G IX is a premium prescription hearing aid released in 2024, priced at $3,398. In our lab testing, it earned an A grade with a SoundScore of 4.6/5, ranking #11 among 39 prescription hearing aids tested. This behind-the-ear device delivers strong performance across several key metrics. Speech clarity in quiet environments scores 3.9/5, which is 0.54 points above the category average—a solid result for everyday conversations. Own-voice comfort is a particular highlight at 3.7/5, scoring a full point above average, suggesting natural sound quality when speaking. Music streaming also performs above average at 3.1/5. Speech understanding in noisy environments scores 2.5/5, which is above the category average by 0.43 points but remains mixed in absolute terms—worth considering if challenging listening situations are common. Feedback handling at 3.6/5 is solid in absolute terms, though it falls 1.12 points below the category average of 4.72/5. The Styletto C&G IX is well-suited for users who prioritize natural own-voice quality and reliable speech clarity in quieter settings. Those frequently in noisy environments or particularly sensitive to feedback may want to compare options. At this price point, competitors like the Phonak Sphere Infinio and Oticon Intent score higher overall, while alternatives like the Rexton Reach R-Li T80 at Costco offer similar sound performance at a lower price.
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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