Anatomy of an Audiogram

As a patient with hearing loss, it is important to understand the basics of how to read and interpret the results of a hearing test, also known as an audiogram. The audiogram (figure 1) is arranged by pitch (also called frequency) similarly to the arrangement of a piano (figure 2).

Figure 1

Severity of hearing loss audiogram

Figure 2

Piano Arrangement

As you follow the graph from left to right, the frequency increases just as the notes to the left of a keyboard are lower pitched and the notes to the right are higher pitched. Low-frequency hearing is responsible for us hearing vowels (a, e, i, o, and u). High-frequency hearing is important for hearing consonant sounds (such as s, th, f, k). High-frequency hearing loss will impact speech clarity, or the ability to discern similarly sounding words. One example would be confusing the word ‘key’ with the word ‘tea’.

It is more common for patients to have high-frequency hearing loss, with better or sometimes normal low-frequency hearing. Thus, patients will often report “I can hear, but not understand” or “everyone mumbles”. This complaint is a common sign of high-frequency hearing loss.

The next aspect of the audiogram to consider is intensity (or volume). As you travel from top to bottom on the audiogram (see figure 1), the loudness of the tone increases. The audiogram is divided into sections based on the severity of the hearing loss. For adults, normal hearing thresholds are typically considered from the range of 0 to 20 (reported in decibels hearing level, or dB HL). As you progress downwards on the chart, the hearing loss is described as mild, moderate, moderately-severe, severe and profound. See figure 3 for a representation of familiar sounds displayed on the audiogram for further reference. Patients will often ask, “what percent of hearing loss do I have?”. This is a reasonable question; however, because hearing loss is specific to frequency, and some frequencies may have more hearing loss than others, reducing the description of hearing loss to a percent number is not an accurate representation of the individual’s audiogram. Thus, you will often hear audiologists report hearing loss such as” mild to severe”, which describes the worst threshold in the lower frequencies to the worst threshold in the higher frequencies. Therefore a “mild to severe” hearing loss would imply worse high-frequency hearing.

Figure 3

Audiogram of Familiar Sounds

Finally, note that the audiologist will test each ear separately. Therefore, the audiogram will have a series of thresholds designed by an X or an O (perhaps a square or a triangle, in some cases). The X or square represents the softest level that the left ear could hear a given frequency and the O or triangle represents the softest level that the right ear could hear a specific frequency. See figure 4 for a representation of right and left hearing thresholds drawn on an audiogram.

Figure 4

Left and Right Hearing Thresholds

As a patient, being able to decipher an audiogram gives you a better understanding of your hearing abilities and limitations, which can help you explain why you may have difficulty hearing some individuals but not others. If you have an audiogram, but would like more assistance interpreting the results, consider scheduling a professional consultation with one of LINNER’s hearing professionals. Our providers would be happy to read any hearing results, and provide you with recommendations for how to hear more clearly.