The number of hearing aid users has increased and continues to do so with younger and younger individuals making use of this technology. With this younger and more active demographic, greater demands have been placed on device manufacturers to ensure more adaptable and dynamic features be included in smaller more discreet devices. More active lifestyles are putting devices to the test in all manners of challenging acoustic environments, one of which is wind.
We rarely hear non hearing aid users complain about wind, so what makes hearing device users so special and unique? It’s all down to the microphone. When the flow of air (i.e., wind) hits it, turbulence (varying sound pressure) is created which is then interpreted as sound. The problem is that speech (also varying sound pressure) can get mixed up and be hard to tell apart from the noise by the hearing aid.
Manufacturers have tried to overcome this by changing over to microphones less susceptible to noise in wind (omnidirectional). This helped, but they were not done there. They decided to take it one step further and introduce noise reducing programs and cancellers. Designed to optimize comfort, these monaural systems work by reducing frequencies (typically those in the lower registers) that are considered the main culprits when it comes to wind.
Even though they’re considered quite successful helping to improve comfort, they are not well known to enhance speech understanding. This is why Speech in Wind came about. Its strict purpose is to improve communication whilst reducing wind noise.
So what makes this different from other wind noise cancellers? Firstly, it’s a binaural and not a monaural system meaning that it uses both hearing aids to communicate with one another. They work together to deduce which side has more and which side has less wind noise. Once known, the speech signal is relayed from the hearing device with the better SNR to the one with the poorer SNR.
But it’s only the low frequencies that need help, right? The low frequencies are most affected and it’s these that need to be replaced on the more affected side. The high frequencies are usually unaffected by the noise, allowing the hearing aid to keep these separate, untouched and intact.
As we can see, it’s not only the wind noise that’s attenuated (i.e. providing comfort) but it’s the better speech signal transferred to the poorer side that enhances speech understanding in this challenging acoustic environment. The maintained high frequencies allow localization cues to be retained.
But where’s all this proof? Several internal and external studies show and corroborate that there are significant improvements in both speech understanding and comfort in areas with wind noise when using Speech in Wind. Most of these can be found on the PhonakPro website for those that interested in gaining deeper insight into Speech in Wind.