Normal Audiogram, but…

From time to time, a patient comes to the office noticing they are struggling with conversations, especially in challenging listening environments.  Sometimes they come in after a big birthday – maybe 40, maybe 50.  They ask, “Is it me?”  They want a baseline, and an explanation of why they are have difficulties when other folks seem to be following the conversation or getting the joke.  So I perform our standard audiometric measures, and often find myself saying “Good news – your audiogram is normal, you understand words clearly in quiet, your middle ear is functioning properly, even the inner ear response is fine – in fact, if you were a baby you’d pass the newborn hearing screening.”

And yet, and yet….   They are still not hearing well in noisy environments.  What is going on?  Perhaps my “Good news” is not so reassuring, as it raises the question of “Well, then, why can’t I hear like I used to?”  This was addressed nicely in a recent article in the ASHA Leader (Koehnke, Lister, and Wambacq).  

Although undetectable with audiometric testing, changes in hearing ability begin in our 40’s and 50’s.  A growing body of research suggests that while hearing acuity may be normal, complex auditory processing at the central (brainstem and brain) level is not what it was in our 20’s and 30’s.  

Remember, there is so much more to accurate hearing than raising the volume.  There is a set of skills we use in listening that are complex and quite amazing:

• Temporal processing is the ability to follow rapid changes in speech and music, and affects our ability to discern the consonants and vowels that define a word.  Temporal processing declines with age.
• Information from speech rhythm and emphasis is also clearly affected by age, and affects ease of communication.
• Separating out one stream of conversation from another (at a restaurant or party) becomes more challenging with age – to me, it is a miracle that we can do this at all!
• Subtle changes in hearing may interact with changes in memory, attention, and processing speed.  One study found that speech “babble” (background speech) adversely affects middle aged people’s ability to retrieve words from working memory.

So – there are “normal” changes in the auditory system as we age that may interfere with listening, especially in background noise.  Hearing thresholds may be normal, so hearing aids are not called for.  Here are some strategies (mostly common sense) for easier listening if normal age-related changes in auditory processing are impacting on daily communication:

• Turn off the radio or TV that interfere with your understanding another’s speech.
• Position yourself and your conversation partners to best see and hear each other.
• Ask conversation partners to speak more loudly, slowly, clearly (whatever would help).
• If other conversations are happening simultaneously, try to relocate.   Separating will help you focus your attention on the conversation of interest.

We may not know exactly which of the many age-related changes may affect our individual auditory systems.  We do know that there are normal changes that occur.  They may affect each of us differently, but if you are not hearing quite as easily as you used to, I hope it is reassuring to know that you are not alone!