Cearvol Diamond X1 vs Olive Union Max
Side-by-side HearAdvisor lab results with SoundGrades, expert pick badges, and the same visualizations we use in product reviews.

Cearvol Diamond X1
The Cearvol Diamond X1 is a budget-priced OTC hearing aid that earned a B grade with a SoundScore of 3.7/5 in our lab testing, placing it in the top 45% of OTC devices. At $199, it represents an accessible entry point for those exploring hearing amplification. The Diamond X1's standout performance is in music streaming, scoring 4.1/5—a strong result that sits 2.18 points above the OTC category average. This makes it notably capable for users who prioritize audio entertainment through their hearing devices. Feedback handling is also excellent at 4.5/5, meaning users should experience minimal whistling during normal use. However, speech performance presents limitations. Speech in quiet scores a mixed 2.8/5, and speech in noise registers at 1.7/5. While both metrics technically sit above category averages (+0.03 and +0.22 points respectively), they remain low in absolute terms—important context for anyone prioritizing conversation clarity. Own-voice comfort is another weakness, scoring 1.7/5, which is 0.81 points below the category average and may affect how natural users sound to themselves. The Diamond X1 is best suited for budget-conscious consumers who value music streaming quality and aren't heavily reliant on challenging listening environments. Those who prioritize speech understanding in noise or natural own-voice perception may want to consider alternatives in this price range, such as the higher-scoring Elehear Beyond or Apple AirPods Pro 2.

Olive Union Max
The Olive Union Max is a behind-the-ear OTC hearing aid priced at $190, earning a B grade with a SoundScore of 3.4/5 in HearAdvisor's lab testing. This budget-friendly device ranks #41 of 65 OTC hearing aids tested. In our lab testing, the Max shows a distinctive performance profile with clear strengths and limitations. Music streaming stands out with a strong 4.0/5 score, measuring 2.08 points above the OTC category average—making it one of the better choices for audio entertainment. Feedback handling is excellent at 5.0/5, meaning the device maintains stability without whistling during typical daily activities. However, speech performance presents challenges. Speech in quiet scores a mixed 2.6/5, falling 0.21 points below the category average, while speech in noise is low at 1.0/5, measuring 0.48 points below average. Own-voice comfort also scores low at 1.6/5, sitting 0.91 points below the category average—users may notice their own voice sounds unnatural or hollow. The Olive Union Max is best suited for budget-conscious consumers who prioritize music and media streaming over demanding listening environments. Those who frequently need to follow conversations in noisy settings like restaurants or social gatherings may find the speech-in-noise limitations frustrating. For basic amplification in quieter environments with excellent streaming quality at an accessible price point, the Max offers reasonable value despite its speech performance trade-offs.
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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