Cearvol Diamond X1 vs Starkey Evolv AI
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.

Starkey Evolv AI
The Starkey Evolv AI is a premium prescription behind-the-ear hearing aid released in 2022, currently available at $4,598. In HearAdvisor's lab testing, it earns a B grade with a SoundScore of 3.9/5, ranking #30 of 39 prescription hearing aids tested. This device shows notable strengths in specific performance areas. Music streaming quality scores a solid 3.7/5, which is +0.94 points above the category average—a meaningful advantage for users who frequently stream audio from their phone. Speech in noise performance also stands out at 2.8/5, sitting +0.66 points above the category average, though this remains a mixed absolute score. Speech in quiet is solid at 3.4/5, essentially matching the category average. The Evolv AI does show some limitations in our testing. Own voice comfort scores 2.1/5, falling -0.60 points below the category average, which may affect how natural your own speech sounds. Feedback handling presents a more significant gap: while the 3.5/5 score is solid in absolute terms, it sits -1.22 points below the category average of 4.72/5, meaning competing prescription devices generally perform better in feedback stability tests. Professional fitting makes a meaningful difference with this device. The normalized Initial Score of 3.8/5 improves to 4.2/5 after tuning, a +0.4 point gain primarily driven by improvements in speech clarity metrics. At this premium price point, several competitors like the Phonak Sphere Infinio and Oticon Intent deliver higher overall scores. The Evolv AI is best suited for users who prioritize music streaming quality and speech understanding in noise, and who have access to professional fitting services to optimize performance.
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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