1. Normal Hearing: -10 to +15 dB HL
Children have better hearing sensitivity than the accepted normal range for adults. A child with hearing sensitivity in the -10 to +15 dB range will detect the complete speech signal even at soft conversation levels. However, good hearing does not guarantee good ability to discriminate speech in the presence of background noise.
2. Minimal (Borderline) 16-25 dB HL
May have difficulty hearing faint or distant speech. At 15 dB, a student can miss up to 10% of speech signal when the teacher is at a distance greater than 3 feet and when the classroom is noisy, especially in the elementary grades when verbal instruction predominates. • May be unaware of subtle conversational cues, which could cause the child to be viewed as inappropriate or awkward. May miss portions of fast-paced peer interaction, which could begin to have an impact on socialization and self concept. May have immature behavior. Child may be more fatigued than classmates due to the additional listening effort needed. • May benefit from mild gain/low MPO hearing instrument or personal FM system dependent on loss configuration. Would benefit from sound field amplification if the classroom is noisy and/or reverberant. Favorable seating will help. May need attention to vocabulary or speech, especially with recurrent otitis medical history. Appropriate medical management necessary for conductive losses. Teacher must be educated to understand the impact of hearing loss on language development and learning.
3. Mild 26-40 dB HL
child can miss 25-40% of speech signal. The degree of difficulty experienced in school will depend upon the noise level in the classroom, distance from teacher and the configuration of the hearing loss. Without amplification, the child with 35-40 dB loss may miss at least 50% of class discussions, especially when voices are faint or the speaker is not in line of vision. Will miss consonants, especially when a high frequency hearing loss is present. Barriers beginning to build, with a negative impact on self esteem as the child is accused of “hearing when he or she wants to,” “daydreaming,” or “not paying attention.” The child begins to lose the ability for selective hearing, and has increasing difficulty suppressing background noise, which makes the learning environment stressful. Child is more fatigued than classmates due to additional listening effort needed. Will benefit from a hearing instrument and use of a personal FM or sound field FM system in the classroom. Needs favorable seating and lighting. Refer to special education for language evaluation and educational follow-up. Needs auditory skill building. May need attention to vocabulary and language development, articulation or speechreading and/or special support in reading. May need help with self esteem. Teacher training required.
4. Moderate 41-55 dB HL
conversational speech at a distance of 3-5 feet (fact-to-face) only if structure and vocabulary are controlled. Without amplification the amount of speech signal missed can be 50% to 75% with 40dB loss and 80% to 100% with 50dB loss. Is likely to have delayed or defective syntax, limited vocabulary, imperfect speech production and an atonal voice quality. Often with this degree of hearing loss, communication is significantly affected, and socialization with peers having normal hearing becomes increasingly difficult. With full-time use of hearing instruments/FM systems, the child may be judged as a less competent learner. There is an increasing impact on self-esteem. Refer to special education for language evaluation and for education follow-up. Amplification is essential (hearing instruments and FM system). Special education support may be needed, especially for primary children. Attention to oral language development, reading and written language is required. Auditory skill development and speech therapy usually needed. Teacher inservice required.
5. Moderate to Severe 56 to 70 dB HL
conversation must be very loud to be understood. A 55 dB loss can cause child to miss up to 100% of speech information. Will have marked difficulty in school situations requiring verbal communication in both one-to-one and group situations. Delayed language, syntax, reduced speech intelligibility and atonal voice quality likely. Full time use of hearing instruments/FM systems may result in child being judged by both peers and adults as a less competent learner, resulting in poorer self concept, social maturity and contributing to a sense of rejection. Inservice to address these attitudes may be helpful. Full time use of amplification is essential. Will need resource teacher or special class depending on magnitude of language delay. May require special help in all language skills, language based academic subjects, vocabulary, grammar, pragmatics as well as reading and writing. Probably needs assistance to expand experiential language base. Inservice of mainstream teachers required.
6. Severe 71 to 90 dB HL
amplification, the child may hear loud voices about one foot from the ear. When amplified optimally, children with hearing ability of 90 dB or better would be able to identify environmental sounds and detect all the sounds of speech. If loss is of prelingual onset, oral language and speech may not develop spontaneously or will be severely delayed. If hearing loss is of recent onset, speech is likely to deteriorate with quality becoming atonal. Child may prefer other children with hearing impairments as friends and playmates. This may further isolate the child from the mainstream. However, these peer relationships may foster improved self concept and a sense of cultural identity. May need full-time special aural/oral program with emphasis on all auditory language skills, speechreading, concept development and speech. As loss approaches 80 – 90 dB, may benefit from a Total Communication approach, especially in the early language learning years. Individual hearing instrument/personal FM system essential. Need to monitor effectiveness of communication modality. Participation in regular classes as much as beneficial to student. Inservice of mainstream teachers essential.
7. Profound 91 dB HL or more
Aware of vibrations more than tonal pattern. Many rely on vision rather than hearing as primary avenue for communication and learning. Detection of speech sounds dependent .