MDHearing Volt 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.

MDHearing Volt
The MDHearing Volt is a budget-priced prescription hearing aid released in 2020, earning a B grade with a SoundScore of 3.0/5 in our lab testing. At $397, it sits in the lowest price tier for prescription devices, ranking #34 of 39 in its category. In our testing, the Volt showed a mixed performance profile with one standout strength: feedback handling scored an excellent 5.0/5, which is 0.28 points above the category average. This means users can expect minimal whistling or squealing during typical wear. However, speech performance was limited, with speech in quiet scoring 1.8/5 (1.65 points below average) and speech in noise at 1.0/5 (1.11 points below average). Own voice comfort was mixed at 2.6/5, roughly matching the category average. Music streaming capability was not functional in our testing, scoring 0.0/5—a significant limitation for users who want to stream audio from their phone. This is 2.76 points below the prescription hearing aid category average. The Volt may appeal to budget-conscious consumers who prioritize basic amplification and feedback-free wear over advanced speech enhancement or streaming features. Those seeking stronger speech performance in the same price range may want to consider alternatives like the RxEars Rxi, which scored 4.07/5 in our testing. The Volt's rechargeable battery and behind-the-ear design offer practical convenience, but its core sound performance reflects its entry-level positioning.
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.
We independently review each item we recommend and appreciate your trust and support. When you buy through our links, we may earn a commission. Learn More.
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