Phonak Sphere Infinio Ultra vs Sontro Soundwave
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.

Sontro Soundwave
The Sontro Soundwave is a mid-priced OTC hearing aid that earns a B grade with a SoundScore of 3.0/5 in our lab testing. At $849, this behind-the-ear device uses disposable batteries and sits in the lower tier of OTC performance, ranking #61 of 65 devices in its category. The Soundwave's strongest attribute is own-voice comfort, scoring 3.6/5—a solid result that sits 1.09 points above the OTC category average. This makes it relatively comfortable for wearers who are sensitive to hearing their own voice sound unnatural or boomy. However, other performance areas present significant limitations. Speech clarity scores are below average in both quiet and noisy environments. Speech in quiet scores 2.7/5 (0.12 points below average), while speech in noise drops to 1.2/5 (0.28 points below average). Feedback handling is a notable weakness at 2.5/5, falling 2.04 points below the category average of 4.54/5. Perhaps most limiting is the music streaming score of 0.0/5, indicating this device does not support phone audio streaming—a feature many competitors in this price range offer. Consumers prioritizing own-voice comfort on a moderate budget may find the Soundwave acceptable, but those seeking strong speech clarity or streaming capability should consider alternatives. Several higher-performing OTC devices are available at similar or lower price points, including options like the Lexie Lumen or HearingAssist Control that deliver comparable or better overall sound quality.
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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