High-frequency Hearing Loss

High-frequency hearing loss causes special problems in understanding speech.

---

Hearing Loss Starts in the High Frequencies

When hearing loss is caused by overexposure to noise or by ordinary aging, sensitivity to high frequencies is the first to go. Sounds with frequencies above about 3000 or 4000 hertz (Hz) become harder to hear.

Speech Frequencies and Speech Discrimination

While it's unfortunate to have any form of hearing loss, high-frequency hearing loss is especially troublesome because this also happens to be the range where much of human speech is transmitted. While vowel sounds are usually safely below this range, certain consonant sounds have primary frequencies above 3000 Hz.

With hearing loss in the high frequencies, the sounds that are hardest to tell apart are f, s, and th. Other unvoiced consonants that might be hard to distinguish are k and t, and sometimes ch and sh. So for example, the following phrases might all sound much alike:

take the cash
chase the cat
shake the sack
fake the stats
taste the catch
face the facts

First Sign of Hearing Loss

If you can't hear these consonants clearly enough to tell them apart, speech will sound jumbled. You may be able to hear people talking well enough, but you sometimes can't quite make out what they're saying. For some people, this is their first clue that they've experienced mild hearing loss. Another sign of high-frequency hearing loss is that men's voices are easier to understand than women's and children's, since men typically have lower-pitched voices.

As hearing loss progresses and affects a wider range of frequencies, speech might start to sound like a string of vowel sounds spaced by indistinct separations.

Why Talking More Loudly Doesn't Help

If you are having trouble understanding what someone is saying, naturally you might ask him or her to speak up. The problem is that when the person speaks more loudly, it affects only the vowels and the voiced consonants — you can't "turn up the volume" on unvoiced consonants. (Have you ever tried to whisper loudly?) So now you have the double frustration that the person is speaking more loudly, and you can probably hear the vowels just fine, but you still can't understand what he or she is saying! If you are in a noisy environment, say perhaps a bar, restaurant, or party, the background noise only adds to the difficulty in hearing speech.

---

Leave this page (High-frequency Hearing Loss) and go → Back to Effects of Noise Pollution
Leave this page (High-frequency Hearing Loss) and go → Back to Noise Help home page

---