Back to Comparisons
Product Comparison

Cearvol Diamond X1 vs Otofonix Helix

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

Uses Official HearAdvisor Lab Data
Cearvol Diamond X1 Hero
CearvolSoundScore 3.7Grade B

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.

Otofonix Helix Hero
OtofonixSoundScore 2.6Grade C

Otofonix Helix

The Otofonix Helix is a behind-the-ear amplification product released in 2021, priced at $695. In HearAdvisor's lab testing, it earned a C grade with a SoundScore of 2.6/5, ranking #7 of 8 devices in the Amplification Product category. The Helix demonstrates one clear strength: excellent feedback handling at 5.0/5, which is 0.72 points above the category average. This means users are unlikely to experience whistling or squealing during typical use. However, the device shows significant limitations in other areas. Speech clarity scores are low in both quiet (1.0/5) and noisy (1.0/5) environments, falling below category averages by 1.11 and 0.37 points respectively. Own-voice comfort is notably weak at 0.3/5 in the tuned configuration, measuring 2.34 points below the category average. This suggests users may find their own voice sounds unnatural or boomy. Music streaming capability scored 0.0/5, indicating this device is not suitable for those who want to stream audio content. Consumers in this price range have substantially higher-performing alternatives available. The Sennheiser Conversation Clear Plus scores 4.04/5, while the HearingAssist Micro achieves 3.54/5. Those seeking similar performance at a lower price point might consider the Otofonix Encore or RCA Micro. The Helix may appeal to users who prioritize feedback-free amplification over speech clarity or streaming features, but most shoppers will find better value elsewhere in this category.

We independently review each item we recommend and appreciate your trust and support. When you buy through our links, we may earn a commission. Learn More.

Performance metrics

Scale 1-5 (Tuned)

Lab metric by fit

Scale 1-5 (Tuned)

Speech in quietNew
Cearvol Diamond X12.8
Otofonix Helix1.0
Speech in noiseNew
Cearvol Diamond X11.7
Otofonix Helix1.0
Own voice
Cearvol Diamond X11.7
Otofonix Helix0.3
Feedback handling
Cearvol Diamond X14.5
Otofonix Helix5.0
Music streaming
Cearvol Diamond X14.1
Otofonix Helix0.0
Overall fit score
Cearvol Diamond X13.8
Otofonix Helix2.5

Speech level

Adjust input dB (Tuned)

Amplification (REIG)

Insertion gain at 65 dB (Tuned)

Audio scenes

Recorded samples (Tuned)

Otofonix Helix: No recording for this scene.

Fitting configuration for tuned fit

Cearvol Diamond X1Otofonix Helix
Ear CouplingClosed Dome
Ear CouplingClosed Dome