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

Linner Mars
The Linner Mars is a budget-priced OTC hearing aid that earns a B grade with a SoundScore of 3.1/5 in our lab testing. At $399, it falls in the lowest price tier for OTC devices, though its overall sound performance ranks #55 of 65 in the OTC Hearing Aid category. This device presents a stark contrast in performance across different listening situations. Music streaming is a genuine standout, scoring an excellent 4.6/5—well above the category average. Feedback handling also earns a perfect 5.0/5, meaning users shouldn't experience whistling or squealing issues. However, the Mars struggles significantly with its core hearing aid function: speech clarity. Speech in quiet scores just 1.9/5, and speech in noise drops to 1.0/5, both falling below category averages. Own-voice comfort is another weak point at 1.0/5, which is 1.51 points below the category average. Users may find their own voice sounds unnatural or boomy when wearing these devices. The tuned fit shows modest improvement over the initial fit (3.4/5 vs 3.1/5), primarily through better speech-in-quiet performance. The Linner Mars may appeal to budget-conscious consumers who prioritize music and media streaming over speech understanding. However, several competitors in the same price range—including the Elehear Beyond and Apple AirPods Pro 2—offer substantially better overall sound performance. Those seeking improved speech clarity should consider alternatives that score higher in that critical area.

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