Results of the audiometric evaluation are plotted on a chart called an audiogram. Loudness is plotted from top to bottom. Frequency, from low to high, is plotted from left to right. Hearing loss (HL) is measured in decibels (dB) and is described in general categories. Hearing loss is not measured in percentages. The general hearing loss categories used by most hearing professionals are as follows:
- Normal hearing (0 to 25 dB HL)
- Mild hearing loss (26 to 40 dB HL)
- Moderate hearing loss (41 to 70 dB HL)
- Severe hearing loss (71 to 90 dB HL)
- Profound hearing loss (greater than 91 dB HL)
Mild hearing loss: Patients with mild hearing loss may experience trouble hearing soft sounds, increased difficulty in background noise, and struggle to hear things from a distance.
Moderate hearing loss: Patients with moderate degrees of hearing loss may feel like people are mumbling, frequently misunderstand words, and feel that hearing in background noise is extremely difficult.
Severe hearing loss: Patients with severe degrees of hearing loss are frequently not able to follow a conversation without requesting people to speak up or repeat. Typically environmental sounds like leaves rustling, turn signals, and birds are not heard.
Profound hearing loss: Most sounds of the world are not heard. Loud sound such as fire alarms, telephone rings, and traffic are not heard. Speech is not audible unless someone is shouting.