MDHearing VoltMax vs Phonak Sphere Infinio
Side-by-side HearAdvisor lab results with SoundGrades, expert pick badges, and the same visualizations we use in product reviews.

MDHearing VoltMax
The MDHearing VoltMax is a behind-the-ear OTC hearing aid priced at $699, earning a B grade with a SoundScore of 3.0/5 in our lab testing. This places it in the lower tier of the OTC hearing aid category, ranking 62nd out of 65 devices tested. In our testing, the VoltMax delivered mixed results across key performance areas. Its standout strength is excellent feedback handling, scoring a perfect 5.0/5—above the category average by 0.46 points. This means users can expect stable performance without whistling or squealing during typical daily activities. However, speech clarity proved challenging, with speech-in-quiet scoring 1.9/5 (0.93 points below category average) and speech-in-noise at 1.0/5 (0.48 points below average). Own-voice comfort measured 2.4/5, slightly below the category norm. A significant limitation is music streaming, which scored 0.0/5—nearly 2 points below the category average. Users who prioritize phone streaming for calls or media should consider alternatives. The device features rechargeable batteries, offering convenience over disposable options. At this price point, several competitors deliver substantially stronger overall performance. The VoltMax may appeal to budget-conscious consumers who primarily need basic amplification with reliable feedback control and don't require streaming capabilities. Those seeking better speech clarity or music streaming should explore higher-scoring options in this price range.
Choice

Phonak Sphere Infinio
The Phonak Sphere Infinio is a premium behind-the-ear prescription hearing aid released in 2024, priced at $4,898. In our lab testing, it earned an A grade with a SoundScore of 5.0/5, placing it at #2 among 39 prescription hearing aids tested—within the top 3% of its category. The standout performance comes in speech clarity. Speech in noise scores an excellent 4.7/5, a remarkable 2.59 points above the category average of 2.11/5. Speech in quiet also impresses at 4.5/5, sitting 1.07 points above average. For anyone who struggles to follow conversations in restaurants, gatherings, or busy environments, this device delivers measurably superior intelligibility compared to most alternatives we've tested. Music streaming quality is strong at 4.0/5, exceeding the category average by 1.24 points—a meaningful advantage for users who value audio fidelity when streaming from phones. However, own-voice comfort is mixed at 2.3/5, falling 0.40 points below the category average, which may affect how natural your own speech sounds. Feedback handling, while solid in absolute terms at 3.6/5, sits 1.12 points below the category average of 4.72/5. The Sphere Infinio is best suited for users prioritizing exceptional speech understanding, particularly in challenging noise environments, and who are willing to invest at the premium tier. Those especially sensitive to own-voice quality or requiring maximum feedback stability may want to compare alternatives like the similarly-priced Oticon Intent or the lower-priced Phonak Audéo EON Sphere.
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)
Audio scenes
Recorded samples (Tuned)
Fitting configuration for tuned fit