Severity of Hearing Loss 

Hearing loss is measured by the inability to hear soft sounds and is displayed in an audiogram, as shown in the figure. An audiogram plots the level of a pure tone needed to reach the listener’s absolute threshold (‘I can just hear it’) at each test frequency relative to the level needed by young listeners with normal hearing (NH). An ordinate value of 0 dB on an audiogram indicates no hearing loss at that test frequency. Larger degrees of loss result in larger ordinate values, which are plotted going down.  

Although hearing losses come in many patterns, the most common is like those shown in the figure labeled HL1-HL5. Hearing loss at low frequencies is relatively constant and increases for higher frequencies. This is the pattern that is usually seen with presbycusis, the hearing loss that often accompanies old age. The simulated hearing losses HL1 through HL5 that are demonstrated here all have the same pattern; they differ only in their severity.

This demo presents three sentences and two music passages processed through the five simulated hearing losses as well as normal hearing. 

Because the same sentence (or music passage) is used for each degree of loss, start with HL5, the most severe loss, and proceed to less severe losses (i.e., go from left to right across a row in the table below). If you start with NH and hear the sentence clearly, it will be hard to estimate the intelligibility with worse losses because you will already know the sentence.

Click here to open the HeLPS Severity of Hearing Loss Demo in a new window.