MDHearing VoltMax vs Sony CRE-C20
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.

Sony CRE-C20
The Sony CRE-C20 is a mid-priced OTC hearing aid with an invisible-in-ear design, available for $999. In our lab testing, it earned a B grade with a SoundScore of 3.5/5, ranking #37 of 65 OTC hearing aids tested. This device shows a notable split in performance. Speech clarity is a clear strength—speech in quiet scores 4.1/5, which is 1.33 points above the category average, and speech in noise scores 2.7/5, sitting 1.24 points above average despite being only mixed in absolute terms. These results suggest the CRE-C20 prioritizes conversational intelligibility in its tuning approach. However, the device has significant limitations. Music streaming scored 0.0/5, falling 1.92 points below the category average—a notable weakness for users who want to stream audio. Feedback handling is solid at 3.9/5, though it sits 0.64 points below the category average of 4.54/5. Own voice comfort is mixed at 2.9/5, slightly above the category average. The CRE-C20 responds well to adjustment, with the normalized score improving from 3.3/5 at initial fit to 4.2/5 when tuned—a 0.9-point gain. Buyers focused primarily on speech understanding in conversations may find value here, but those wanting music streaming or seeking the strongest overall OTC performance should note that several competitors in this price range, including the Sony CRE-E10 at 4.66/5, scored higher in our testing.
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