Hearing loss is often considered simply a matter of volume, as though turning the sound up is all that is needed to fix the problem. But for many people, the challenge isn’t that everything sounds too quiet. It’s that certain sounds, especially speech, are no longer clear.
Most everyday speech falls within a specific, narrow range of frequencies. When hearing loss affects this range, a person may still hear voices but struggle to understand what is said.
Reduced Audibility of Sounds
High-frequency consonants like “s,” “f,” “th,” “t,” and “k” are often the first to become difficult to hear when someone has hearing loss in the higher frequency range. These soft, sharp sounds carry much of the detail that makes speech clear and understandable.
This all comes down to which frequencies are affected:
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Low-frequency hearing loss makes it harder to hear vowel sounds like “a,” “e,” “o,” and “u.” As a result, speech may sound soft or distant, as though people are mumbling.
For example, the word “open” might sound like “pn,” or “audio” might be heard as “dio.” -
High-frequency hearing loss, which is more common, affects consonant sounds like “s,” “f,” “th,” “t,” and “k.” These are soft but critical for understanding speech.
For example, “sat” might be heard as “at,” “think” as “ink,” and “fast” as “fat” or even just “at.”
Even though the person hears someone is speaking, the finer details of what is being said are lost, making it hard to follow conversations, especially in group settings or noisy environments.
The Speech Banana
The speech banana is a visual tool that shows where the sounds of human speech fall on an audiogram (a chart that measures hearing ability across different pitches and loudness levels).
Most vowel sounds, like “a” and “o,” fall into the lower frequency range and are relatively loud. These tend to remain audible even with mild hearing loss. Many consonants sit in the higher frequencies and lower intensities.
This means that someone might hear the voice but miss the meaning because key consonant sounds fall outside their hearing range.
An image of the speech banana is shown below to illustrate how these sounds are spread across the frequency spectrum, and which ones may be affected by hearing loss.
Poor Speech Discrimination
Even when volume is sufficient, a person with hearing loss may still struggle to distinguish between similar-sounding words. This is known as poor speech discrimination, and it often stems from damage in the inner ear or auditory pathways that process sound.
Words may blend or sound distorted, making it difficult to differentiate between “fit” and “sit,” or “cap” and “cat.” This can happen even in quiet environments where background noise isn’t a factor.
To better understand the nature of this difficulty, audiologists use a few key tools during a hearing test:
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SAT (Speech Awareness Threshold): Measures the softest level at which a person can detect the presence of speech, not necessarily understand it, just be aware that someone is talking.
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SRT (Speech Reception Threshold): Determines the lowest level at which a person can correctly repeat simple, familiar words about 50% of the time. This tells us how much volume is needed for speech to become recognizable.
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WRS (Word Recognition Score): Evaluates how clearly someone can understand words at a comfortable volume. A low WRS suggests that even with amplification (such as a hearing aid), the person may still struggle to understand speech accurately.
These tests help reveal not just how much a person can hear, but how well they understand what they’re hearing; a critical distinction when it comes to addressing real-world communication challenges.
When speech starts to sound unclear or muffled, the issue isn’t always volume; it’s often missing sounds within a specific frequency range. High-frequency hearing loss can make everyday conversations feel challenging, even when you can still hear voices.
Hearing aids can help bring access to those missing sounds, especially soft consonants that are key to speech clarity. But for them to work well, they need to be precisely tuned to your specific hearing loss. A one-size-fits-all approach rarely delivers the clarity people are hoping for.
Getting the right hearing aids and having them properly fitted can make speech clearer, reduce listening effort, and help you stay fully connected to the world around you.
