Here are the categories of hearing loss, and how you can expect your child to hear speech.
This diagram shows the categories of hearing loss - the further towards the bottom of the graph, the more severe the hearing loss. A few speech sounds are also plotted, indicating the approximate frequency (pitch) and intensity (loudness) of each sound. the speech sounds are plotted at levels of loudness if they were spoken in average conversational loudness in a quiet environment.
Speech sounds differ in terms of frequency (pitch) and intensity (loudness). Vowel sounds such as 'a', 'e', 'i', 'o' and 'u', tend to be lower in frequency (pitch) and louder in intensity. Consonants such as 's', 'p', 't', 'sh', 'k', and 'f' tend to be higher in frequency (pitch) and softer in intensity. How much hearing loss your child has will determine how he or she will be able to hear normal conversational speech.
Normal hearing (0-15dB): Your child will likely be able to detect and discriminate all speech sounds even at very quiet levels.
Slight (20-25dB) and Mild hearing loss (25-40dB): Your child might have difficulty hearing faint or distant speech and have difficulty in group environments. Your child will likely be able to hear sounds at close distances and in quiet environments.
Moderate (40-55dB) and Moderately-Severe hearing loss (55-70dB): Your child might have difficulty detecting and discriminating consonants (e.g., the s, sh, th, ch, f, k, and p sounds) and might rely on combined clues from several sounds, words, and patterns of speech to understand what is said.
Severe hearing loss (70-90dB): Your child might be able to identify environmental sounds; he or she might be able to discriminate vowels but will likely have difficulty discriminating consonants.
Profound hearing loss (90-105dB): Your child will likely only hear loud environmental sounds and feel vibrations.
Children often have hearing loss that is a combination of different levels for different pitches. An example is a mild hearing loss in the low pitches and a severe hearing loss in the high pitches.
Follow Up - Recommended Next Steps
Untreated hearing loss can have significant negative effects on speech and language development.
Early intervention services (or early communication support services), medical treatment and/or hearing devices can significantly minimize the negative effects of hearing loss. Use of sign language, hearing aids or other hearing devices are usually needed for permanent hearing loss.
You should work with your audiologist and other professionals to be sure to get appropriate treatment and a follow-up plan for your child’s hearing loss.