WindBlock 2.0: Comfort and clarity outdoors

From walking with a friend to spending time on the golf course or sharing a picnic on the beach, outdoor activities often involve conversation. Yet wind can get in the way, turning an ordinary outdoor conversation into hard work. And this is not just a problem on blustery days. Even relatively mild airflow across hearing aid microphones can interfere with speech and increase listening effort.

Not only that but a younger and more diverse population is entering the hearing aid market,¹ and expectations of what hearing devices should deliver are changing. Comfort matters, but so does being able to stay connected while moving through the world.

Wind noise can compromise more than sound quality. It can degrade speech intelligibility and make communication outdoors difficult, potentially limiting participation in activities that clients value.^2,3

Why wind is such a difficult signal to manage

Hearing aid microphones are designed to detect the air pressure fluctuations created by sound waves. Ironically, this design is exactly what makes microphones vulnerable to wind as well.

When wind strikes the ear or the hearing aid itself, the resulting turbulence generates pressure fluctuations at the microphone inlet. These fluctuations can be picked up as  a kind of phantom signal, something the hearing aid registers as sound even though it  has no true acoustic source.⁴  

The human ear has some natural protection against this: the tragus and the shape of the ear canal help attenuate wind-induced pressure before it reaches the eardrum. Exposed hearing aid microphones, however, do not have the same protection.

Wind noise occupies a strange category: it isn’t really a sound, and it isn’t really noise in the traditional sense. It is an artefact created by the interaction between airflow and the microphone, making it a difficult issue to resolve. Complicating things further, wind noise is unpredictable and fluctuates with gusts and changing direction.^4,5

It can also arise from the hearing aid’s own movement, so even a light breeze or a brisk walk can be enough to trigger it.^2,6 And unlike steady-state noise such as traffic or crowd chatter, wind noise is broadband but most intense at the low end of the spectrum, right where important information (e.g., vowels and other key speech cues) is also present.^4,5

It’s not only hearing aid microphones that are susceptible to wind noise. Outdoor news reporters, sports commentators, and content creators all face the same problem, which is why microphones used in the field are routinely fitted with a windscreen, sometimes referred to as a “dead cat” cover.

These fluffy shields deflect and disrupt airflow while allowing sound to pass through.⁶ Hearing aids, for obvious reasons, cannot accommodate this type of windscreen. Instead wind noise must be managed internally.

From WindBlock to WindBlock 2.0

Phonak’s existing wind noise canceller, WindBlock, addressed this by continuously monitoring the two hearing aid microphones and looking for uncorrelated low-frequency signals, an acoustic signature of wind.⁶ When detected, it applies up to 23 dB of attenuation below 1 kHz; users consistently preferred it over no wind management at all.^6,7

However, this approach comes with a tradeoff: it cannot distinguish wind from real sound in the same frequency region, so speech in that range can also be reduced. WindBlock 2.0 was designed to address this limitation by reducing wind noise while preserving speech information.

WindBlock 2.0 is guided by two observations: wind noise is uncorrelated across microphones, and in most real-world conditions, the rear microphone experiences less wind than the front. WindBlock 2.0 starts from the rear microphone signal and applies a dynamic gain based on the cross-correlation between front and rear inputs.

The portion correlated with the front microphone, largely speech, is preserved, while the uncorrelated wind noise is suppressed. In situations where the front microphone happens to be less affected by wind than the rear, a fallback mode automatically emphasizes the front signal instead.

What was measured

Technical measurements were taken using a KEMAR mannequin in a wind tunnel at Sonova headquarters in Stäfa, Switzerland. The measurements showed:⁸

• Substantially more wind noise reduction: Up to 50 dB of wind noise reduction with WindBlock 2.0 compared with WindBlock 2.0 switched off.
• A meaningfully improved signal-to-noise ratio: An SNR benefit of up to 30 dB, compared with WindBlock 2.0 switched off off.
• Preservation of low-frequency speech information: Spectrogram analysis showed distinct low-frequency speech energy retained below 1 kHz, rather than being suppressed along with the wind as can occur with the original WindBlock.
• Improved listening experience in wind: Clients reported a more natural and comfortable listening experience in wind compared with the previous generation.

What this means in practice

WindBlock 2.0 is designed for situations where wind would otherwise interfere with conversation, such as talking while walking or spending time outdoors. It runs automatically, across all performance levels, so the benefit is there whenever wind picks up. Because wind shouldn’t get in the way of conversation.

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Want to learn more? Read the Field Study News to explore the evidence behind WindBlock 2.0 and its benefits for speech clarity, listening comfort, and sound quality in wind. And for further details on the evidence behind WindBlock 2.0 and other EON features, visit phonak.com/evidence.

References:

1. Jilla, A. M., & Jorgensen, L. (2025). Hearing aid adoption in the OTC hearing aid era: Market trends and consumer insights from MarkeTrak 2025. Seminars in Hearing, 46(3), 184–195.
2. Latzel, M., & Appleton, J. (2013a). Evaluation of a binaural speech in wind feature, Part 1: Verification in the Laboratory. Hearing Review, 20(8), 32–34. Retrieved from https://hearingreview.com/hearing-products/evaluation-of-a-binaural-speech-in-wind-feature-part-1-verification-in-the-laboratory-2
3. Sarampalis, A., Kalluri, S., Edwards, B., & Hafter, E. (2009). Objective measures of listening effort: Effects of background noise and noise reduction. Journal of Speech, Language, and Hearing Research, 52(5), 1230–1240.
4. Cook, M. R., Gee, K. L., Transtrum, M. K., Lympany, S. V., & Calton, M. (2021). Automatic classification and reduction of wind noise in spectral data. JASA Express Letters, 1(6), 063602.
5. Chung, K., McKibben, N., & Mongeau, L. (2009). Wind noise in hearing aids with directional and omnidirectional microphones: Polar characteristics of behind-the-ear hearing aids. The Journal of the Acoustical Society of America, 125, 2243–2259.
6. Phonak. (2012). Speech in Wind: Bringing more than just comfort in wind noise. Phonak Insight. Retrieved from https://www.phonak.com/evidence
7. Latzel, M., & Appleton, J. (2013b). Evaluation of a binaural speech in wind feature, part 2: Validation and real-life benefit. Hearing Review, 20(9), 32–35. https://hearingreview.com/hearing-products/36-evaluation-of-a-binaural-speech-in-wind-feature-part-2-validation-and-real-life-benefit
8. Vaisberg, J. M., Brunner, J., & Ulloa Sanchez, D. (2026). Hearing confidently in the wind: WindBlock 2.0 delivers comfort, natural sound quality and clearer speech. Phonak Field Study News. Retrieved from https://www.phonak.com/evidence