Otofonix Helix 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.

Otofonix Helix
The Otofonix Helix is a behind-the-ear amplification product released in 2021, priced at $695. In HearAdvisor's lab testing, it earned a C grade with a SoundScore of 2.6/5, ranking #7 of 8 devices in the Amplification Product category. The Helix demonstrates one clear strength: excellent feedback handling at 5.0/5, which is 0.72 points above the category average. This means users are unlikely to experience whistling or squealing during typical use. However, the device shows significant limitations in other areas. Speech clarity scores are low in both quiet (1.0/5) and noisy (1.0/5) environments, falling below category averages by 1.11 and 0.37 points respectively. Own-voice comfort is notably weak at 0.3/5 in the tuned configuration, measuring 2.34 points below the category average. This suggests users may find their own voice sounds unnatural or boomy. Music streaming capability scored 0.0/5, indicating this device is not suitable for those who want to stream audio content. Consumers in this price range have substantially higher-performing alternatives available. The Sennheiser Conversation Clear Plus scores 4.04/5, while the HearingAssist Micro achieves 3.54/5. Those seeking similar performance at a lower price point might consider the Otofonix Encore or RCA Micro. The Helix may appeal to users who prioritize feedback-free amplification over speech clarity or streaming features, but most shoppers will find better value elsewhere in this category.
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.
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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)
Audio scenes
Recorded samples (Tuned)
Fitting configuration for tuned fit