(Central) Auditory Processing Disorder (C)APD

Children and adults with APD have trouble understanding language despite having normal hearing. In simple terms, the ear is fine but the brain has difficulty processing or interpreting the information it receives.

Behavioural auditory processing evaluation can be done for people with:

• Normal or near-normal peripheral hearing
• Sufficient receptive and expressive language skills to understand and respond to the tasks
• Sufficient cognitive function
• Seven years of age is usually considered the lower age limit for APD testing (adults can also be candidates for APD evaluation.

Some possible symptoms likely to be seen in the general population of children with APD are:

• Respond inconsistently to auditory stimuli e.g. seems to follow auditory instructions inconsistently
• Have trouble listening in the presence of noise
• Have trouble with auditory localisation - determining where a sound is coming from
• Show sensitivity to loud noises or certain frequencies
• Have generally poor listening skills and decreased attention for auditory information
• Easily distractible and restless in listening situations
• Have difficulty understanding rapid speech or unclear speech
• Have difficulty understanding speech in the presence of background noise (e.g. speech in noisy environments or crowds) or in a reverberant room (e.g. when acoustics are poor and where sounds echo)
• Frequently ask that information be repeated. Says “huh?” or “what?” repeatedly
• Have significant difficulties with reading, writing, and spelling
• Have trouble associating speech sounds to their symbols (letters)
• Perform better in small groups and one-to-one setting
• Give inappropriate responses to questions
• Insensitive to speaker’s tone of voice
• Suffer from poor self-esteem or frustration
• Have delays in speech and language development
• Have trouble discriminating one sound from another (especially speech sounds)
• Have trouble remembering information that has been presented in the auditory mode

A comprehensive multidisciplinary approach led by an audiologist is important to identify APD.

An Audiologist will first carry out tests to rule out peripheral hearing loss and middle ear pathologies. A background of the family, educational qualifications, social emotional concerns, behavioural and medical history are helpful in the assessment battery.

A number of tonal and speech tests are then carried out to assess auditory memory, discrimination and other auditory processes which include the binaural integration, binaural separation, temporal patterning, temporal processing and binaural interaction skills.

Some of the symptoms of APD are similar to that of other learning disorders such as language delay, attention deficit disorders, cognitive delay and dyslexia. As a result, the audiologist may recommend a referral to other professionals to determine whether another disorder is the root cause of the child's difficulties and/or whether the child has APD. These professionals may include speech-language pathologists, educational psychologists, paediatricians and occupational therapists.

Management plans are tailored jointly between the audiologist and speech-language therapist to suit individual auditory processing deficit profile. These may include some or all of the following:

Speech-language therapists provide therapy activities that directly target the auditory processes that the child has difficulty in, and at an appropriate level of difficulty. At least one family member is encouraged to attend the therapy sessions with the patient because successful remediation requires consistent practice. Where appropriate, computer-based programmes may be recommended.

Some of these include the development of listening strategies to avoid auditory fatigue and improving language skills to improve understanding of degraded auditory signals.

Some modifications in the classroom may be sufficient to help some children listen and process better. Preferential seating in the classroom to allow for additional visual cues may help a child with APD. Cutting down on background noises by closing the door or using a classroom with friendlier acoustics may also be recommended. The child may also benefit from an assistive listening device (FM system) that allows the child to hear the teacher directly whilst cutting out background noise.