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

Signia Styletto AX
The Signia Styletto AX is a premium prescription behind-the-ear hearing aid that earned an A grade with a SoundScore of 4.3/5 in our lab testing, ranking #21 of 39 prescription hearing aids tested. Priced at $4,398, this 2022 release features a distinctive slim design with rechargeable batteries and iPhone streaming capability. In our testing, the Styletto AX demonstrated strong speech clarity in quiet environments, scoring 4.0/5—0.63 points above the category average. Speech in noise performance was above average at 2.3/5 (+0.17 vs category), though this remains mixed in absolute terms, suggesting challenging listening situations may still require additional strategies. Own-voice comfort scored a solid 3.0/5, sitting 0.30 points above average. Music streaming quality measured 3.1/5, performing 0.34 points above the category average for solid audio fidelity when streaming from compatible devices. Feedback handling scored 3.9/5—solid in absolute terms, though 0.82 points below the category average of 4.72/5, which is worth noting if feedback stability is a priority. The Styletto AX has earned Expert's Choice Awards in both 2023 and 2024. However, buyers in this premium price tier should be aware that several competitors offer higher SoundScores, including the Phonak Sphere Infinio (4.98/5) and Oticon Intent (4.83/5). The Styletto AX may appeal most to those prioritizing its sleek aesthetic and strong quiet-environment speech performance over maximum scores in noise or feedback handling.

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.
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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