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

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.

Sontro Soundwave
The Sontro Soundwave is a mid-priced OTC hearing aid that earns a B grade with a SoundScore of 3.0/5 in our lab testing. At $849, this behind-the-ear device uses disposable batteries and sits in the lower tier of OTC performance, ranking #61 of 65 devices in its category. The Soundwave's strongest attribute is own-voice comfort, scoring 3.6/5—a solid result that sits 1.09 points above the OTC category average. This makes it relatively comfortable for wearers who are sensitive to hearing their own voice sound unnatural or boomy. However, other performance areas present significant limitations. Speech clarity scores are below average in both quiet and noisy environments. Speech in quiet scores 2.7/5 (0.12 points below average), while speech in noise drops to 1.2/5 (0.28 points below average). Feedback handling is a notable weakness at 2.5/5, falling 2.04 points below the category average of 4.54/5. Perhaps most limiting is the music streaming score of 0.0/5, indicating this device does not support phone audio streaming—a feature many competitors in this price range offer. Consumers prioritizing own-voice comfort on a moderate budget may find the Soundwave acceptable, but those seeking strong speech clarity or streaming capability should consider alternatives. Several higher-performing OTC devices are available at similar or lower price points, including options like the Lexie Lumen or HearingAssist Control that deliver comparable or better overall sound quality.
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