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

iHear MatriX
The iHear MatriX is a budget-priced OTC hearing aid that earns a B grade with a SoundScore of 3.8/5, placing it in the top 40% of the OTC hearing aid category in our lab testing. At $499, this behind-the-ear device delivers solid speech performance that exceeds category averages, though with a notable tradeoff in streaming capabilities. Speech clarity is a clear strength for the MatriX. In quiet environments, it scores 4.0/5—a solid result that sits 1.17 points above the OTC category average. Speech in noise performance is more modest at 2.4/5, which is mixed in absolute terms but still 0.96 points above the typical OTC device. Feedback handling is excellent at 5.0/5, meaning users should experience minimal whistling during daily wear. The most significant limitation is music streaming, which scores 0.0/5—well below the category average of 1.92/5. While the MatriX supports both iPhone and Android streaming, audio fidelity for music is poor in our testing. Own-voice comfort is mixed at 2.7/5, roughly in line with category norms. The MatriX shows meaningful improvement with tuning, jumping from an Initial Score of 3.7/5 to a Tuned Score of 4.2/5. This suggests users who invest time in adjustment can unlock better performance. For budget-conscious buyers prioritizing speech understanding over music quality, the MatriX offers competitive value in its price range, though alternatives like the Elehear Beyond score higher overall at similar pricing.

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.
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