Children with APD have difficulties processing the meaning of sounds

"Auditory processing disorder (APD), also known as central auditory processing disorder (CAPD), refers to the reduced ability to process auditory information. Simply put, it is a difficulty in processing and decoding sounds," ​say speech therapists ​from the ​Speech Therapy Department​ from Singapore General Hospital (SGH), a member of the SingHealth​ group.​

People with APD often have normal hearing abilities but exhibit difficulty in tasks that require them to decipher and process the meaning of sounds. People with APD are a heterogeneous group, with individuals presenting with different profiles of difficulty. These difficulties may manifest as problems in identifying the locations of sounds, differentiating between similar sounds and differentiating speech from background noise, to name a few.

APD is estimated to affect between 2 to 5 per cent of children in Western countries. The figures for Singaporean children, unfortunately, are not known.

Signs of APD

Some common characteristics of APD are:

  • Poor comprehension especially in noisy environments
  • Frequent use of “huh?” or “what?”
  • Difficulty following directions
  • Poor phonics skills
  • ​Inattentiveness
  • High distractibility
  • Difficulty following conversations
  • Academic difficulties

What causes APD?

Unfortunately, the cause of APD is still unknown. It is suspected that APD may stem from an abnormal representation of auditory information in the brain. This could be a result of varying factors, such a delay of the development of the central auditory nervous system. Children with neurological disorder or trauma to the brain may also present with APD.

There is no relationship between intelligence and APD as many children with intelligence levels in the normal range have APD. APD is also a characteristic of other disorders, including, but not limited to, autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), dyslexia and language impairments.

How is APD diagnosed?

APD is diagnosed by an audiologist and requires the use of standardised tests and calibrated equipment. It cannot be diagnosed from general observation. Although other professionals may be involved in the identification and treatment of APD, it is the audiologists who conduct the assessment and determine the diagnosis of APD. The assessment of APD involves a series of specially controlled hearing tasks that look at the following processing abilities:

  • locating the source of a sound
  • differentiating between similar sounds (e.g. /p/ and /b/)
  • recognising patterns of speech
  • stringing sounds together and perceiving them as meaningful speech
  • distinguishing speech sounds from other competing sounds
  • processing and understanding incomplete auditory information

As certain aspects of auditory processing only fully develops as the brain matures, a true assessment and diagnosis of APD can only take place after the child enters primary school, around the age of 7 or 8.

Read on to learn about treatment options for APD and tips to help children with APD.

Ref: O17​