Understanding Hearing Aid Directional Microphones
When looking at different hearing aids, you will come across a wide range of features that may influence your choice of product. Here is everything you need to know about hearing aid directional microphones and why you might benefit from a hearing aid that has these microphones as a feature.
Some hearing aids have a omni-directional microphone, some have a directional microphone and some have a combination of omni-directional microphones and directional or adaptive directional microphones. While early clinical studies pinned omni-directional microphones against directional microphones, most hearing professionals feel hearing aids that have both omni-directional microphones and directional or adaptive directional microphones provide their patients with the most benefit.
1. Omni-Directional Hearing Aid Microphone: Will pick up sound equally from all directions.
2. Directional Hearing Aid Microphone: Will put more emphasis, or focus, on sound coming from in front of the user. Most hearing aids equipped with a directional hearing aid microphone also have a omni-directional hearing aid microphone.
3. Adaptive Directional Hearing Aid Microphones: Hearing Aid will adjust it's focus between surround sound hearing and varied degrees of directional hearing automatically.
What are the benefits of directional microphones?
Directional microphones amplify the sound coming from in front of the person more than the sound coming from beside and behind a person. The goal is to provide better speech intelligibility while communicating in noisy environments and is the main benefit to consider when opting for a hearing aid with a directional microphone.
Sound coming from in front of a person tends to be more relevant than sound coming from beside and behind a person. When surrounding noise is as loud as speech it's very hard for the hearing aid user to understand the speech over the noise, the goal of directional microphones is to elevate the speech coming from in front of a person by focusing on it.
However, it is also worth considering a hearing aid that has both an omni-directional microphone and a directional microphone, as this combination allows for switching between the two microphones in different listening environments. For example, an omni-directional microphone can be optimal for surround sound hearing in quiet environments, just consider the benefits of surround hearing while walking, hiking and biking. While, in a busy restaurant a directional microphone is optimal for hearing table conversation.
Most of the time hearing aids that offer both omni-directional and directional microphones come with multiple programs; one program will utilize the omni-directional microphone and will be known as the program used in quiet environments, while a second program will utilize the directional microphone, and will be known as the program to be used in noisy environments.
What about adaptive directional microphones?
Adaptive directional microphones is the next giant leap in hearing aid microphones and their usefulness is really a marriage of several hardware and software innovations in hearing aid technology. Adaptive directional microphones do just that, they adapt. The hearing aid microphones automatically and dynamically, focus on speech regardless of what direction the speech is coming from. The goal is to improve speech intelligibility in all situations by focusing on speech, while decreasing the level of focus and ultimately amplification applied to competing noise.
Consider a couple out for a night. They start their evening in the vehicle. When they get downtown they park their car and walk a couple blocks down a quiet street until they reach their hotel. They checkin at the front desk and proceed to the busy hotel restaurant for a nice dinner. The benefit of the user wearing advanced digital hearing aids with adaptive directional microphones are that the hearing aids will automatically adjust between omni-directional hearing and varied degrees of directional hearing as the user moves from the car, to the street, to a moderately busy hotel lobby and ultimately to a very busy restaurant.
With adaptive directional microphones the hearing hearing aids DSP, or brain, will tell it to amplify equally from all directions until a person enters an environment wear speech is present. The DSP does everything it can to enhance the signal of speech and reduce the amplification applied to the surrounding noise.
Subsequently, the hearing aid will adjust it's noise filters to minimize the amplification of competing noise so that the hearing aid wearer is not overwhelmed by unnecessary background sounds. Often hearing aids that have adaptive directional microphones also come with multiple programs, however instead of programming one memory for quiet settings and another program for noisy settings, the button is used more as a straight volume control; as the noise filters and microphones adjust automatically.