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Hearing aid users know it all too well: That feeling that you don’t know where a sound is coming from. It’s disconcerting for sure, but there’s a scientific explanation. Knowing more about this phenomenon, called the precedence effect, can help you prepare for it. If it’s really troubling you, Sonora Hearing Care has device options that can help solve this problem.

What Is the Precedence Effect?

The precedence effect, also known as the Haas effect, is a function of having two ears, or hearing in stereo. Your ears are responsible for interpreting sound cues and helping your brain determine where they’re coming from. That’s called sound localization. 

Your ears work together to localize sound, but they’re easily fooled. If two sounds coming from different directions reach your ears within a few milliseconds, your brain will think the second sound is coming from the direction of the first. If the second sound’s origin is far enough away, it might not be heard at all. The sound that arrives first takes precedence over the second sound. 

And, that distance (known as the critical distance) is pretty short. In most regular rooms, it’s no greater than 3 to 6 feet. Beyond that, the precedence effect comes into play, potentially confusing your ears.

Precedence Effect and Directional Mics

Since sound travels slowly—relative to light, at least—that means that, for example, speech coming from across a room has no directional information left by the time it reaches your ears. Any hearing aid user will say that it’s a disconcerting feeling. 

Hearing aids are amplification devices, but the amplified sounds coming from across the room in rapid succession still doesn’t have directional information for your ears to use. It’s a matter of signal to noise: There’s lots of noise, but it’s hard to pick out what you want to actually listen to. 

The solution is a wireless microphone that interacts with your hearing aids. Give the mic to someone you’re speaking to or place it near whatever it is you want to hear, and it beams the sound directly into your hearing aids. In effect, it’s as if what you’re trying to listen to is right in front of you, neutralizing the precedence effect. Ask your audiologist about wireless microphones. At Sonora Hearing Care, we can tell you what options you have based on your hearing aid and make a recommendation for the right microphone for you. If you’re looking for an upgrade to a more modern hearing aid that has wireless microphone integration, we can help with that too. Request an appointment today.