(Olsen et al, 1987; Meuller and Killion, 1990; Northern and Downs, 1991; Hasenstab, 1987; Flexer, 1994).

Unilateral

• one ear with normal hearing, one ear with at least mild difficulty with identifying speech in noise, localizing sound sources even with speech directed at good ear, has more difficulty than child with 2 normal ears.
• Same difficulties as child with slight hearing loss:
  more distractible, frustrated, dependent, less attentive, appears less confident (Culbertson & Gilbert, 1986; Oyler et al, 1988; Stein, 1983)
• behavioural difficulties may be more obvious than hearing difficulties.

With unilateral hearing impairment and repeated ear infections, children are at extreme risk for educational and behavioural difficulties if left unmanaged.

Fluctuating

Hearing is not stable as in cases of Otitis Media (ear infections) of Perilymphatic Fistula (inner ear fluid leaks).

• requires ongoing management including medical management
• very detrimental given inconsistent auditory information
• otitis media can cause hearing impairment of up to 60 dB - moderate-to-severe

Slight

• difficulty hearing faint or distant speech
• can miss up to 10% of speech signal and subtle conversational cues
• has difficulty keeping up with fast paced communicative interactions, faulty abstractions of grammatical rules (Northern and Downs)
• Subtle stress patterns missing- emotional content of speech, rhythm and intonation are communicated through low frequency
• when cues lost, emotional content of speech is confused confusion in segmentation and prosody-miss linguistic boundaries for tense, plurality, possessives, etc.

Even a slight hearing impairment can sabotage the overall development of a child who is learning language and acquiring knowledge (Davis, 1990; Downs, 1988).

Mild

• can miss 25-40% of speech signal with 30dB loss
• can miss 50% with 35-40 dB loss
• will miss consonants, ie., may hear 'eat', 'feet', 'beeped', 'she', 'sleeps' all as "ee"
• difficulty hearing word boundaries
• may be accused of daydreaming, not trying, etc.
• will have more difficulty in noisy situations

With unmanaged loss, children with a mild hearing loss are likely to be at least one grade level behind peers

A slight or mild hearing loss in adults is not all that detrimental because they have knowledge of the linguistic code and are able to fill in information whereas a child who is learning the language does not have knowledge of the linguistic code and therefore cannot fill in information that s/he does not have.

Moderate

• 40 dB loss- miss 50-75% of speech signal
• 50dB loss - miss 80-100% of speech signal
• likely to have delayed syntax (grammar), limited vocabulary, misarticulated speech and atonal voice quality
• communication is significantly affected
• without intervention, likely to be at least 2 grade levels behind by 4th grade
  (Ross, Brackett, & Maxon, 1991)
• spoken communciaton must be very loud and very close to be minimally understood
  c/ 55 dB loss - miss 100% of classroom information (Matkin, 1981) delayed language, syntax, reduced speech intelligibility, atonal voice quality likely will have marked difficulty in school

Severe

• may hear loud noises about 1 foot from the ear
• with appropriate amplification, should be able to detect all the speech sounds but without auditory based intervention (such as AV therapy) may not develop spoken language necessary to learn and live in mainstreamed environments

Profound

• cannot hear speech without amplification
• residual hearing is present in the overwhelming majority of cases
• communicative abilities of these children depends upon a number of factors including:

-amount of residual hearing
-age diagnosed/fitted
-appropriate amplification
-type and intensity of early intervention(From: Flexer, 1994)

Children with profound hearing loss can develop spoken language abilities, function in a mainstreamed environment and lead independent, productive lives in the mainstream of society.
No hearing loss is too little or too great to warrant considerations for amplification and support.