MDHearing Volt vs Phonak Audéo EON Sphere
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 available for $397, earning a B grade with a SoundScore of 3.1/5 in our lab testing. This behind-the-ear, rechargeable device ranks #32 of 36 prescription hearing aids tested, placing it in the top 86% of its category. In our standardized testing, the Volt demonstrates excellent feedback handling at 5.0/5, scoring 0.29 points above the category average. This represents a genuine strength, as the device remained stable under our challenge protocols without audible squealing or whistling. However, speech performance presents significant limitations: speech in quiet scored 1.8/5 (1.57 points below the category average of 3.32), while speech in noise scored 1.0/5 (0.96 points below the 1.96 average). Own-voice comfort measured 2.6/5, a mixed result that falls 0.15 points below the category average. Music streaming is notably limited at 0.0/5, scoring 2.64 points below the category average—users prioritizing phone streaming should consider alternatives. The Volt showed no improvement between Initial and Tuned fits, with both configurations yielding identical scores of 3.1/5. The MDHearing Volt may suit budget-conscious consumers who prioritize basic amplification and excellent feedback stability over speech clarity or streaming features. However, shoppers in this price range should note that alternatives like the RxEars Rxi offer substantially higher performance at similar pricing.
Choice

Phonak Audéo EON Sphere
The Phonak Audéo EON Sphere is a premium behind-the-ear prescription hearing aid priced at $4,398. In HearAdvisor's lab testing, it earned a SoundScore of 5.0/5 and an A grade, placing it among the top performers in the prescription hearing aid category. Speech performance stands out as this device's greatest strength. Speech in noise scored an excellent 4.5/5, a full 2.53 points above the category average of 1.96/5—a substantial margin that makes this one of the strongest performers in challenging listening environments. Speech in quiet also performed well at 4.3/5, nearly a full point above the category average. These results suggest the Audéo EON Sphere may be particularly well-suited for users who frequently encounter noisy social settings or group conversations. Music streaming delivered a solid 3.7/5, more than a point above the category average of 2.64/5, indicating above-average audio fidelity for phone-streamed content. Own-voice comfort scored 2.8/5, which sits just above the category average but reflects mixed absolute performance—users sensitive to occlusion effects should discuss this with their hearing care provider. Feedback handling scored an excellent 4.6/5 in absolute terms, though it lands slightly below the category average of 4.71/5. The Audéo EON Sphere represents Phonak's latest premium technology and delivers strong results across most metrics in our standardized testing. It's best suited for users prioritizing speech clarity in difficult listening situations who are prepared for the premium price point.
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