Our lab tested the Cearvol Diamond X1 using standardized acoustic measurements and real-ear verification to evaluate how this budget OTC hearing aid performs across speech clarity, noise handling, and streaming quality.
Dr. Steve Taddei, Au.D. — Lab Director & Reviewer
Dr. Abram Bailey, Au.D. — Fact Checker / Editor
The Cearvol Diamond X1 is a budget-friendly OTC option with standout music streaming for casual listeners who prioritize entertainment over speech clarity.
Top 45% of OTC Hearing AidEach curve shows how the Diamond X1 scored in speech in quiet, speech in noise, own-voice comfort, feedback control, and music quality. The purple SoundScore graph is the overall result, and the five graphs after it break it into individual measurements for the selected fit. Each curve shows how scores are spread across all tested hearing aids, and the dot and number mark the score for Cearvol Diamond X1.
Every hearing aid is lab-tested in two states — as it sounds out of the box, and after professional tuning. Switch fits to update the five metric graphs below.
How clearly speech comes through in calm, one-on-one surroundings.
Speech understanding against loud background noise — the toughest everyday test.
How natural your own voice sounds while wearing the aids, without a boomy, plugged-up quality.
Sound quality of music streamed to the hearing aids over Bluetooth.
Resistance to the whistling and squealing caused by acoustic feedback.
Lab Assessment
Quality data starts with quality recordings. HearAdvisor worked with GRAS to build a no-compromise front end so every test is repeatable and reliable.
Amplification Analysis
The graph below plots the measured amplification the Diamond X1 provides across frequencies against established prescription targets. This comparison reveals how closely the device matches the gain profile intended for hearing correction.
Audio Samples
These samples were captured through a standardized acoustic manikin to document what the Diamond X1 delivers to the ear canal. Compare them against the reference recording to hear the processing applied by the device.
How this hearing aid sounds in our lab scenes. Compare it out of the box and after professional tuning.
Scene type: Conversation
164 lab recordings of this product. They demonstrate relative processing in our lab and cannot predict an individual fitting outcome.
Test Documentation
Our technicians documented observations from both Initial and Tuned fit conditions during testing. The notes below detail the specific settings and any fit-related factors that may have influenced measured performance.
In its initial fit configuration with closed domes, the Cearvol Diamond X1 achieved a normalized Initial Score of 3.7/5. Speech in quiet measured 2.5/5 and speech in noise 1.5/5—both limited results for conversational use. Music streaming performed strongly at 4.1/5, while feedback handling was excellent at 4.5/5. Own-voice comfort scored 1.7/5, suggesting some users may notice occlusion effects when speaking.
After tuning adjustments (maintaining closed dome coupling), the Diamond X1 improved to a normalized Tuned Score of 3.8/5—a modest 0.2-point gain. Speech in quiet rose to 2.8/5 and speech in noise to 1.7/5, representing incremental improvements in audibility. Music streaming, feedback handling, and own-voice scores remained unchanged at 4.1/5, 4.5/5, and 1.7/5 respectively, indicating tuning benefits were concentrated in speech metrics.
Initial Fitting | Tuned Fitting | |
|---|---|---|
| Ear Coupling | Closed Dome | Closed Dome |
