Auditory processing disorder
|Auditory processing disorder|
|Classification and external resources|
Auditory processing disorder (APD), also known as central auditory processing disorder (CAPD), is an umbrella term for a variety of disorders that affect the way the brain processes auditory information. Individuals with APD usually have normal structure and function of the outer, middle and inner ear (peripheral hearing). However, they cannot process the information they hear in the same way as others do, which leads to difficulties in recognizing and interpreting sounds, especially the sounds composing speech. It is thought that these difficulties arise from dysfunction in the central nervous system (i.e., brain).
APD does not feature in mainstream diagnostic classifications such as the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV). The American Academy of Audiology notes that APD is diagnosed by difficulties in one or more auditory processes known to reflect the function of the central auditory nervous system.
APD can affect both children and adults, although the actual prevalence is currently unknown. It has been suggested that males are twice as likely to be affected by the disorder as females, but there are no good epidemiological studies.
The American Speech-Language-Hearing Association (ASHA) published "(Central) Auditory Processing Disorders" in January 2005 as an update to the "Central Auditory Processing: Current Status of Research and Implications for Clinical Practice (ASHA, 1996)". The American Academy of Audiology has released more current practice guidelines related to the disorder
In 2011, the British Society of Audiology published 'best practice guidelines'.
Auditory processing disorder can be developmental or acquired. It may result from ear infections, head injuries or neurodevelopmental delays that affect processing of auditory information. This can include problems with: "...sound localization and lateralization (see also binaural fusion); auditory discrimination; auditory pattern recognition; temporal aspects of audition, including temporal integration, temporal discrimination (e.g., temporal gap detection), temporal ordering, and temporal masking; auditory performance in competing acoustic signals (including dichotic listening); and auditory performance with degraded acoustic signals."
The Committee of UK Medical Professionals Steering the UK Auditory Processing Disorder Research Program have developed the following working definition of Auditory Processing Disorder: "APD results from impaired neural function and is characterized by poor recognition, discrimination, separation, grouping, localization, or ordering of speech sounds. It does not solely result from a deficit in general attention, language or other cognitive processes."
The first research into APD began in 1954 with Helmer Myklebust’s study, "Auditory Disorders in Children". Myklebust’s work suggested auditory processing disorder was separate from language learning difficulties. His work sparked interest in auditory deficits after acquired brain lesions affecting the temporal lobes and led to additional work looking at the physiological basis of auditory processing, but it was not until the late seventies and early eighties that research began on APD in depth. In 1977, a conference about APD started a new series of studies focussing on APD in children. Virtually all tests currently used to diagnose APD originate from this work. These early researchers also invented many of the auditory training approaches, including interhemispheric transfer training and interaural intensity difference training. This period gave us a rough understanding of the causes and possible treatment options for APD. Much of the work in the late nineties and 2000s has been looking to refining testing, developing more sophisticated treatment options, and looking for genetic risk factors for APD. Scientists have worked on improving behavioral tests of auditory function, neuroimaging, electroacoustic, and electrophysiologic testing. Working with new technology has led to a number of software programs for auditory training. With global awareness of mental disorders and increasing understanding of neuroscience, auditory processing is more in the public and academic consciousness than ever before.
APD is a difficult disorder to detect and diagnose. The subjective symptoms that lead to an evaluation for APD include an intermittent inability to process verbal information, leading the person to guess to fill in the processing gaps. There may also be disproportionate problems with decoding speech in noisy environments.
APD has been defined anatomically in terms of the integrity of the auditory areas of the nervous system. However, children with symptoms of APD typically have no evidence of neurological disease and the diagnosis is made on the basis of performance on behavioral auditory tests. Auditory processing is "what we do with what we hear", and in APD there is a mismatch between peripheral hearing ability (which is typically normal) and ability to interpret or discriminate sounds. Thus in those with no signs of neurological impairment, APD is diagnosed on the basis of auditory tests. There is, however, no consensus as to which tests should be used for diagnosis, as evidenced by the succession of task force reports that have appeared in recent years. The first of these occurred in 1996. This was followed by a conference organized by the American Academy of Audiology. Experts attempting to define diagnostic criteria have to grapple with the problem that a child may do poorly on an auditory test for reasons other than poor auditory perception: for instance, failure could be due to inattention, difficulty in coping with task demands, or limited language ability. In an attempt to rule out at least some of these factors, the American Academy of Audiology conference explicitly advocated that for APD to be diagnosed, the child must have a modality-specific problem, i.e. affecting auditory but not visual processing. However, an ASHA committee subsequently rejected modality-specificity as a defining characteristic of auditory processing disorders.
The issue of modality-specificity has led to considerable debate among experts in this field. Cacace and McFarland have argued that APD should be defined as a modality-specific perceptual dysfunction that is not due to peripheral hearing loss. They criticise more inclusive conceptualizations of APD as lacking diagnostic specificity. A requirement for modality-specificity could potentially avoid including children whose poor auditory performance is due to general factors such as poor attention or memory. Others, however, have argued that a modality-specific approach is too narrow, and that it would miss children who had genuine perceptual problems affecting both visual and auditory processing. It is also impractical, as audiologists do not have access to standardized tests that are visual analogs of auditory tests. The debate over this issue remains unresolved. It is clear, however, that a modality-specific approach will diagnose fewer children with APD than a modality-general one, and that the latter approach runs a risk of including children who fail auditory tests for reasons other than poor auditory processing. Although modality-specific testing has been advocated for well over a decade, to date no tests have been published which would allow audiologists to perform a modality-specific evaluation (i.e., no clinical versions of visual analogs to auditory processing tests exist).
Another controversy concerns the fact that most traditional tests of APD use verbal materials. The British Society of Audiology has embraced Moore's (2006) recommendation that tests for APD should assess processing of non-speech sounds. The concern is that if verbal materials are used to test for APD, then children may fail because of limited language ability. An analogy may be drawn with trying to listen to sounds in a foreign language. It is much harder to distinguish between sounds or to remember a sequence of words in a language you do not know well: the problem is not an auditory one, but rather due to lack of expertise in the language.
In recent years there have been additional criticisms of some popular tests for diagnosis of APD. Tests that use tape-recorded American English have been shown to over-identify APD in speakers of other forms of English. Performance on a battery of non-verbal auditory tests devised by the Medical Research Council's Institute of Hearing Research was found to be heavily influenced by non-sensory task demands, and indices of APD had low reliability when this was controlled for.
Depending on how it is defined, APD may share common symptoms with ADD/ADHD, Specific language impairment, Asperger syndrome and other forms of autism. A review showed substantial evidence for atypical processing of auditory information in autistic children. Dawes and Bishop noted how specialists in audiology and speech-language pathology often adopted different approaches to child assessment, and they concluded their review as follows: "We regard it as crucial that these different professional groups work together in carrying out assessment, treatment and management of children and undertaking cross-disciplinary research." In practice, this seems rare.
Acquired auditory processing disorder
Acquired APD can be caused by any damage to or dysfunction of the central auditory nervous system and can cause auditory processing problems. For an overview of neurological aspects of APD, see Griffiths.
Developmental auditory processing disorder
In the majority of cases of developmental APD, the cause is unknown. An exception is acquired epileptic aphasia or Landau-Kleffner syndrome, where a child's development regresses, with language comprehension severely affected. The child is often thought to be deaf, but normal peripheral hearing is found. In other cases, suspected or known causes of APD in children include delay in myelin maturation, ectopic (misplaced) cells in the auditory cortical areas, or genetic predisposition. In a family with autosomal dominant epilepsy, seizures which affected the left temporal lobe seemed to cause problems with auditory processing. In another extended family with a high rate of APD, genetic analysis showed a haplotype in chromosome 12 that fully co-segregated with language impairment.
Hearing begins in utero, but the central auditory system continues to develop for at least the first decade. There is considerable interest in the idea that disruption to hearing during a sensitive period may have long-term consequences for auditory development. One study showed thalamocortical connectivity in vitro was associated with a time sensitive developmental window and required a specific cell adhesion molecule (lcam5) for proper brain plasticity to occur. This points to connectivity between the thalamus and cortex shortly after being able to hear (in vitro) as at least one critical period for auditory processing. Another study showed that rats reared in a single tone environment during critical periods of development had permanently impaired auditory processing. ‘Bad’ auditory experiences, such as temporary deafness by cochlear removal in rats leads to neuron shrinkage. In a study looking at attention in APD patients, children with one ear blocked developed a strong right-ear advantage but were not able to modulate that advantage during directed-attention tasks.
In the 1980s and 1990s, there was considerable interest in the role of chronic Otitis media (middle ear disease or 'glue ear') in causing APD and related language and literacy problems. Otitis media with effusion is a very common childhood disease that causes a fluctuating conductive hearing loss, and there was concern this may disrupt auditory development if it occurred during a sensitive period. Consistent with this, in a sample of young children with chronic ear infections recruited from a hospital otolargyngology department, increased rates of auditory difficulties were found later in childhood. However, this kind of study will suffer from sampling bias because children with otitis media will be more likely to be referred to hospital departments if they are experiencing developmental difficulties. Compared with hospital studies, epidemiological studies, which assesses a whole population for otitis media and then evaluate outcomes, have found much weaker evidence for long-term impacts of otitis media on language outcomes.
The National Institute on Deafness and Other Communication Disorders state that children with Auditory Processing Disorder often:
- have trouble paying attention to and remembering information presented orally, and may cope better with visually acquired information
- have problems carrying out multi-step directions given orally; need to hear only one direction at a time
- have poor listening skills
- need more time to process information
- have low academic performance
- have behavior problems
- have language difficulties (e.g., they confuse syllable sequences and have problems developing vocabulary and understanding language)
- have difficulty with reading, comprehension, spelling, and vocabulary
APD can manifest as problems determining the direction of sounds, difficulty perceiving differences between speech sounds and the sequencing of these sounds into meaningful words, confusing similar sounds such as "hat" with "bat", "there" with "where", etc. Fewer words may be perceived than were actually said, as there can be problems detecting the gaps between words, creating the sense that someone is speaking unfamiliar or nonsense words. Those suffering from APD may have problems relating what has been said with its meaning, despite obvious recognition that a word has been said, as well as repetition of the word. Background noise, such as the sound of a radio, television or a noisy bar can make it difficult to impossible to understand speech, since spoken words may sound distorted either into irrelevant words or words that don't exist, depending on the severity of the auditory processing disorder. Using a telephone can be problematic for someone with auditory processing disorder, in comparison with someone with normal auditory processing, due to low quality audio, poor signal, intermittent sounds and the chopping of words. Many who have auditory processing disorder subconsciously develop visual coping strategies, such as lip reading, reading body language, and eye contact, to compensate for their auditory deficit, and these coping strategies are not available when using a telephone.
As noted above, the status of APD as a distinct disorder has been queried, especially by speech-language pathologists and psychologists, who note the overlap between clinical profiles of children diagnosed with APD and those with other forms of specific learning disability. Many audiologists, however, would dispute that APD is just an alternative label for dyslexia, SLI, or ADHD, noting that although it often co-occurs with these conditions, it can be found in isolation.
Relation to specific language impairment and developmental dyslexia
There has been considerable debate over the relationship between APD and Specific language impairment (SLI).
SLI is diagnosed when a child has difficulties with understanding or producing spoken language for no obvious cause. The problems cannot be explained in terms of peripheral hearing loss. The child is typically late in starting to talk, and may have problems in producing speech sounds clearly, and in producing or understanding complex sentences. Some theoretical accounts of SLI regard it as the result of auditory processing problems. However, this view of SLI is not universally accepted, and others regard the main difficulties in SLI as stemming from problems with higher-level aspects of language processing. Where a child has both auditory and language problems, it can be hard to sort out cause-and-effect.
Similarly with developmental dyslexia, there has been considerable interest in the idea that for some children reading problems are downstream consequences of difficulties in rapid auditory processing. Again, cause and effect can be hard to unravel. This is one reason why experts such as Moore have recommended using non-verbal auditory tests to diagnose APD.
If, as is commonly done, APD is assessed using tests that involve identifying, repeating or discriminating speech, then a child may do poorly because of primary language problems. In a study comparing children with a diagnosis of dyslexia and those with a diagnosis of APD, they found the two groups could not be distinguished. obtained similar findings in studies comparing children diagnosed with SLI or APD. The two groups had very similar profiles. This raises the worrying possibility that the diagnosis that a child receives may be largely a function of the specialist they see: the same child who would be diagnosed with APD by an audiologist may be diagnosed with SLI by a speech-language therapist or with dyslexia by a psychologist.
Remediation and training
There is a lack of well-conducted evaluations of intervention using randomized controlled trial methodology. Most evidence for effectiveness adopts weaker standards of evidence, such as showing that performance improves after training. This does not control for possible influences of practice, maturation, or placebo effects. Recent research has shown that practice with basic auditory processing tasks (i.e. auditory training) may improve performance on auditory processing measures and phonemic awareness measures. Changes after auditory training have also been recorded at the physiological level. Many of these tasks are incorporated into computer-based auditory training programs such as Earobics and Fast ForWord, an adaptive software available at home and in clinics worldwide, but overall, evidence for effectiveness of these computerised interventions in improving language and literacy is not impressive. One small-scale uncontrolled study reported successful outcomes for children with APD using auditory training software.
Treating additional issues related to APD can result in success. For example, treatment for phonological disorders (difficulty in speech) can result in success in terms of both the phonological disorder as well as APD. In one study, speech therapy improved auditory evoked potentials (a measure of brain activity in the auditory portions of the brain).
While there is evidence that language training is effective for improving APD, there is no current research supporting the following APD treatments:
- Auditory Integration Training typically involves a child attending two 30-minute sessions per day for ten days.
- Lindamood-Bell Learning Processes (particularly, the Visualizing and Verbalizing program)
- Physical activities that require frequent crossing of the midline (e.g., occupational therapy)
- Sound Field Amplification
- Neuro-Sensory Educational Therapy
- Asperger syndrome
- Attention-Deficit Hyperactivity Disorder
- Auditory scene analysis
- Auditory verbal agnosia
- Cocktail party effect
- Cognitive science
- Cortical deafness
- Dichotic listening test
- Echoic memory
- Hearing (sense)
- King-Kopetzky syndrome (now included in the UK Medical Research Councils definition of APD)
- Language processing
- Multisensory integration
- Rapid automatized naming
- Spatial hearing loss
- "Clinical practice guidelines – diagnosis, treatment, and management of children and adults with central auditory processing" (pdf). American Academy of Audiology.
- La Trobe University. "(C)APD". Retrieved 14 November 2010.
- Musiek, Frank; Gail, Chermak (2007). Handbook of central auditory processing disorder [auditory neuroscience and diagnosis]. Plural Publishing. p. 448. ISBN 1-59756-056-1.
- "Central Auditory Processing: Current Status of Research and Implications for Clinical Practice. Technical Report, (1996)". Working Group on Auditory Processing Disorders. American Speech-Language-Hearing Association.
- British Society of Audiology (2011). "British Society of Audiology Best Practice Guidelines.".
- "(Central) Auditory Processing Disorders. Technical Report, (2005).". Working Group on Auditory Processing Disorders. American Speech-Language-Hearing Association.
- "The British Society of Audiology and the UK APD Steering Group".
- Myklebust, H. (1954). Auditory disorders in children. New York: Grune & Stratton.
- Bocca E, Calearo C, Cassinari V (1954). "A new method for testing hearing in temporal lobe tumours; preliminary report". Acta Oto-laryngologica 44 (3): 219–21. doi:10.3109/00016485409128700. PMID 13197002.
- Bocca E, Calearo C, Cassinari V, Migliavacca F (1955). "Testing "cortical" hearing in temporal lobe tumours". Acta Oto-laryngologica 45 (4): 289–304. doi:10.3109/00016485509124282. PMID 13275293.
- Kimura, Doreen (1961). "Cerebral dominance and the perception of verbal stimuli.". Canadian Journal of Psychology/Revue canadienne de psychologie 15 (3): 166–171. doi:10.1037/h0083219. ISSN 0008-4255.
- Katz, J., & Illmer, R. (1972). Auditory perception in children with learning disabilities. In J. Katz (Ed.), Handbook of clinical audiology (pp. 540–563). Baltimore: Williams & Wilkins.
- Keith, Robert W. (1977). Central auditory dysfunction: University of Cincinnati Medical Center Division of Audiology and Speech Pathology symposium. New York: Grune & Stratton. ISBN 0-8089-1061-2. OCLC 3203948.
- Sweetow RW, Reddell RC (1978). "The use of masking level differences in the identification of children with perceptual problems". J Am Audiol Soc 4 (2): 52–6. PMID 738915.
- Manning WH, Johnston KL, Beasley DS (February 1977). "The performance of children with auditory perceptual disorders on a time-compressed speech discrimination measure". J Speech Hear Disord 42 (1): 77–84. doi:10.1044/jshd.4201.77. PMID 839757.
- Willeford, J. A.; (1977). "Assessing central auditory behavior in children A test battery approach". In Keith, Robert W. Central auditory dysfunction. New York: Grune & Stratton. pp. 43–72. ISBN 0-8089-1061-2. OCLC 3203948.
- Jerger J, Thibodeau L, Martin J, et al. (September 2002). "Behavioral and electrophysiologic evidence of auditory processing disorder: a twin study". J Am Acad Audiol 13 (8): 438–60. PMID 12371661.
- Estes RI, Jerger J, Jacobson G (February 2002). "Reversal of hemispheric asymmetry on auditory tasks in children who are poor listeners". J Am Acad Audiol 13 (2): 59–71. PMID 11895008.
- Chermak GD, Musiek FE (2002). "Auditory training: Principles and approaches for remediating and managing auditory processing disorders". Seminars in Hearing 23 (4): 287–295. doi:10.1055/s-2002-35878. ISSN 0734-0451.
- Musiek F (June 1999). "Habilitation and management of auditory processing disorders: overview of selected procedures". J Am Acad Audiol 10 (6): 329–42. PMID 10385875.
- Task Force on Central Auditory Processing Consensus Development (1996). "Central auditory processing: Current status of research and implications for clinical practice [Technical Report]". American Journal of Audiology 5: 41–54. doi:10.1044/policy.TR1996-00241.
- Jerger J, Musiek F (October 2000). "Report of the Consensus Conference on the Diagnosis of Auditory Processing Disorders in School-Aged Children" (pdf). J Am Acad Audiol 11 (9): 467–74. PMID 11057730.
- Keith, Robert W. (1981). Central auditory and language disorders in children. San Diego, CA: College-Hill Press. ISBN 0-933014-74-0. OCLC 9258682.
- Katz, Jack; Henderson, Donald; Stecker, Nancy Austin (1992). Central auditory processing: a transdisciplinary view. St. Louis, MO: Mosby Year Book. ISBN 1-55664-372-1. OCLC 2587728.
- Katz, Jack; Stecker, Nancy Austin (1998). Central auditory processing disorders: mostly management. Boston: Allyn and Bacon. ISBN 0-205-27361-0. OCLC 246378171.
- Rintelmann, W.F. (1985). "Monaural speech tests in the detection of central auditory disorders.". In Marilyn L Pinheiro and Frank E Musiek. Assessment of central auditory dysfunction : foundations and clinical correlates. Baltimore: Williams & Wilkins. pp. 173–200. ISBN 978-0-683-06887-0. OCLC 11497885.
- Katz, Jack (1992). "Classification of auditory processing disorders". In Jack Katz and Nancy Austin Stecker and Donald Henderson. Central auditory processing : a transdisciplinary view. St. Louis: Mosby Year Book. pp. 81–92. ISBN 978-1-55664-372-9. OCLC 25877287.
- Jerger J, Musiek F (October 2000). "Report of the Consensus Conference on the Diagnosis of Auditory Processing Disorders in School-Aged Children" (pdf). J Am Acad Audiol 11 (9): 467–74. PMID 11057730.
- Cacace, Anthony T.; Dennis J. McFarland (July 1995). "Opening Pandora's Box: The Reliability of CAPD Tests". American Journal of Audiology 4 (2): 61–62. Retrieved 2010-08-31.
- Cacace, Anthony T.; Dennis J. McFarland (December 2005). "The Importance of Modality Specificity in Diagnosing Central Auditory Processing Disorder". American Journal of Audiology 14 (2): 112–123. doi:10.1044/1059-0889(2005/012). PMID 16489868. Retrieved 2010-08-31.
- Cacace, Anthony T.; Dennis J. McFarland (April 1998). "Central Auditory Processing Disorder in School-Aged Children A Critical Review". Journal of Speech, Language, and Hearing Research 41 (2): 355–373. PMID 9570588. Retrieved 2010-08-31.
- Moore, David R. (2006). "Auditory processing disorder (APD): Definition, diagnosis, neural basis, and intervention". Audiological Medicine 4 (1): 4–11. doi:10.1080/16513860600568573.
- Dawes, P; Bishop, D.V. M. (2007). "The SCAN-C in testing for auditory processing disorder in a sample of British children.". International Journal of Audiology 46: 780–786. doi:10.1080/14992020701545906.
- Moore, D.R.; Ferguson, M.A.; Edmondson-Jones, A.M.; Ratib, S; Riley, A (2010). "Nature of auditory processing disorder in children.". Pediatrics 126 (2): e382–390. doi:10.1542/peds.2009-2826.
- O'Connor K (December 2011). "Auditory processing in autism spectrum disorder: A review". Neurosci Biobehav Rev 36 (2): 836–54. doi:10.1016/j.neubiorev.2011.11.008. PMID 22155284.
- Dawes P, Bishop D (2009). "Auditory processing disorder in relation to developmental disorders of language, communication and attention: a review and critique". Int J Lang Commun Disord 44 (4): 440–65. doi:10.1080/13682820902929073. PMID 19925352.
- Musiek FE, Chermak GD, Weihing J, Zappulla M, Nagle S (June 2011). "Diagnostic accuracy of established central auditory processing test batteries in patients with documented brain lesions". J Am Acad Audiol 22 (6): 342–58. doi:10.3766/jaaa.22.6.4. PMID 21864472.
- Lew HL, Weihing J, Myers PJ, Pogoda TK, Goodrich GL (2010). "Dual sensory impairment (DSI) in traumatic brain injury (TBI)--An emerging interdisciplinary challenge". NeuroRehabilitation 26 (3): 213–22. doi:10.3233/NRE-2010-0557. PMID 20448311.
- Griffiths, T. D. (2002). "Central auditory pathologies.". British Medical Bulletin 63 (1): 107–120. doi:10.1093/bmb/63.1.107.
- Fandiño M, Connolly M, Usher L, Palm S, Kozak FK (January 2011). "Landau-Kleffner syndrome: a rare auditory processing disorder series of cases and review of the literature". Int. J. Pediatr. Otorhinolaryngol. 75 (1): 33–8. doi:10.1016/j.ijporl.2010.10.001. PMID 21074868.
- Weihing, Jeff; Musiek, Frank; (2007). "15 Dichotic Interaural Intensity Difference (DIID)". In Ross-Swain, Deborah; Geffner, Donna S;. Auditory Processing Disorders: Assessment, Management and Treatment. Plural Publishing Inc. ISBN 1-59756-107-X. OCLC 255602759.
- Boscariol M, Garcia VL, Guimarães CA, et al. (April 2010). "Auditory processing disorder in perisylvian syndrome". Brain Dev. 32 (4): 299–304. doi:10.1016/j.braindev.2009.04.002. PMID 19410403.
- Bamiou DE, Campbell NG, Musiek FE, et al. (April 2007). "Auditory and verbal working memory deficits in a child with congenital aniridia due to a PAX6 mutation". Int J Audiol 46 (4): 196–202. doi:10.1080/14992020601175952. PMID 17454233.
- Pisano T, Marini C, Brovedani P, Brizzolara D, Pruna D, Mei D, Moro F, Cianchetti C, Guerrini R (January 2005). "Abnormal phonologic processing in familial lateral temporal lobe epilepsy due to a new LGI1 mutation". Epilepsia 46 (1): 118–23. doi:10.1111/j.0013-9580.2005.26304.x. PMID 15660777.
- Addis L, Friederici AD, Kotz SA, Sabisch B, Barry J, Richter N, Ludwig AA, Rübsamen R, Albert FW, Pääbo S, Newbury DF, Monaco AP (August 2010). "A locus for an auditory processing deficit and language impairment in an extended pedigree maps to 12p13.31-q14.3". Genes, Brain, and Behavior 9 (6): 545–61. doi:10.1111/j.1601-183X.2010.00583.x. PMC 2948670. PMID 20345892.
- Moore DR (2002). "Auditory development and the role of experience". British Medical Bulletin 63: 171–81. doi:10.1093/bmb/63.1.171. PMID 12324392.
- Thai-Van H, Veuillet E, Norena A, Guiraud J, Collet L (March 2010). "Plasticity of tonotopic maps in humans: influence of hearing loss, hearing aids and cochlear implants". Acta Otolaryngol. 130 (3): 333–7. doi:10.3109/00016480903258024. PMID 19845491.
- Barkat TR, Polley DB, Hensch TK (September 2011). "A critical period for auditory thalamocortical connectivity". Nature Neuroscience 14 (9): 1189–94. doi:10.1038/nn.2882. PMC 3419581. PMID 21804538.
- Han YK, Köver H, Insanally MN, Semerdjian JH, Bao S (September 2007). "Early experience impairs perceptual discrimination". Nature Neuroscience 10 (9): 1191–7. doi:10.1038/nn1941. PMID 17660815.
- Asbjørnsen A, Holmefjord A, Reisaeter S, Møller P, Klausen O, Prytz B, Boliek C, Obrzut JE (July 2000). "Lasting auditory attention impairment after persistent middle ear infections: a dichotic listening study". Developmental Medicine and Child Neurology 42 (7): 481–6. doi:10.1111/j.1469-8749.2000.tb00352.x. PMID 10972421.
- Whitton JP, Polley DB (October 2011). "Evaluating the perceptual and pathophysiological consequences of auditory deprivation in early postnatal life: a comparison of basic and clinical studies". J. Assoc. Res. Otolaryngol. 12 (5): 535–47. doi:10.1007/s10162-011-0271-6. PMC 3173557. PMID 21607783.
- Hartley DE, Moore DR (June 2005). "Effects of otitis media with effusion on auditory temporal resolution". International Journal of Pediatric Otorhinolaryngology 69 (6): 757–69. doi:10.1016/j.ijporl.2005.01.009. PMID 15885328.
- Feldman, H.M.; et al (2003). "Parent-reported language skills in relation to otitis media during the first 3 years of life". Journal of Speech, Language and Hearing Research 46: 273–287. doi:10.1044/1092-4388(2003/022).
- "Auditory Processing Disorder in Children [NIDCD Health Information]".
- Anderson S, Kraus N (October 2010). "Sensory-cognitive interaction in the neural encoding of speech in noise: a review". J Am Acad Audiol 21 (9): 575–85. doi:10.3766/jaaa.21.9.3. PMC 3075209. PMID 21241645.
- Kamhi, A.G. (2011). "What speech-language pathologists need to know about Auditory Processing Disorder.". Language Speech and Hearing Services in Schools 42 (3): 265–272. doi:10.1044/0161-1461(2010/10-0004).
- Lovett, B.J. (2011). "Auditory processing disorder: School psychologist beware?". Psychology in the Schools 48: 855–867. doi:10.1002/pits.20595.
- Chermak, Gail D (2001). "Auditory processing disorder: An overview for the clinician". Hearing Journal 54 (7): 10–25. doi:10.1097/01.HJ.0000294109.14504.d8.
- Miller, C. A. (2011). "Auditory processing theories of language disorders: Past, present, and future.". Language Speech and Hearing Services in Schools 42 (3): 309–319. doi:10.1044/0161-1461(2011/10-0040).
- Ferguson, M. A.; Hall, R. L.; Riley, A; Moore, D. R. (2011). "Communication, listening, cognitive and speech perception skills in children with auditory processing disorder (APD) or specific language impairment (SLI)". Journal of Speech Language and Hearing Research 54 (1): 211–227. doi:10.1044/1092-4388(2010/09-0167).
- Pindzola, Rebekah H.; Haynes, William O.; Moran, Michael J. (2006). Communication disorders in the classroom: an introduction for professionals in school setting. Boston: Jones and Bartlett Publishers. p. 251. ISBN 0-7637-2743-1. OCLC 59401841.
- Dawes, P; Bishop, D (2010). "Psychometric profile of children with auditory processing disorder (APD) and children with dyslexia". Archives of Disease in Childhood 95: 432–436. doi:10.1136/adc.2009.170118.
- Miller, C.A.; Wagstaff, D.A. (2011). "Behavioral profiles associated with auditory processing disorder and specific language impairment.". Journal of Communication Disorders 44 (6): 745–763. doi:10.1016/j.jcomdis.2011.04.001.
- Corriveau K, Pasquini E, Goswami U (June 2007). "Basic auditory processing skills and specific language impairment: a new look at an old hypothesis". J. Speech Lang. Hear. Res. 50 (3): 647–66. doi:10.1044/1092-4388(2007/046). PMID 17538107.
- Dlouha O, Novak A, Vokral J (June 2007). "Central auditory processing disorder (CAPD) in children with specific language impairment (SLI). Central auditory tests". Int. J. Pediatr. Otorhinolaryngol. 71 (6): 903–7. doi:10.1016/j.ijporl.2007.02.012. PMID 17382411.
- Chermak GD, Silva ME, Nye J, Hasbrouck J, Musiek FE (May 2007). "An update on professional education and clinical practices in central auditory processing". J Am Acad Audiol 18 (5): 428–52; quiz 455. doi:10.3766/jaaa.18.5.7. PMID 17715652.
- Moore DR (2007). "Auditory processing disorders: acquisition and treatment". J Commun Disord 40 (4): 295–304. doi:10.1016/j.jcomdis.2007.03.005. PMID 17467002.
- Moore DR, Rosenberg JF, Coleman JS (July 2005). "Discrimination training of phonemic contrasts enhances phonological processing in mainstream school children". Brain Lang 94 (1): 72–85. doi:10.1016/j.bandl.2004.11.009. PMID 15896385.
- Russo NM, Nicol TG, Zecker SG, Hayes EA, Kraus N (January 2005). "Auditory training improves neural timing in the human brainstem". Behav. Brain Res. 156 (1): 95–103. doi:10.1016/j.bbr.2004.05.012. PMID 15474654.
- Alonso R, Schochat E (2009). "The efficacy of formal auditory training in children with (central) auditory processing disorder: behavioral and electrophysiological evaluation". Braz J Otorhinolaryngol 75 (5): 726–32. doi:10.1590/S1808-86942009000500019. PMID 19893943.
- Loo, J.H.Y.; Bamiou, D.-E.; Campbell, N.; Luxon, L.M. (2010). "Computer-based auditory training (CBAT): benefits for children with language- and reading-related learning difficulties". Developmental Medicine and Child Neurology 52 (8): 708–717. doi:10.1111/j.1469-8749.2010.03654.x.
- Cameron S, Dillon H (November 2011). "Development and Evaluation of the LiSN & Learn Auditory Training Software for Deficit-Specific Remediation of Binaural Processing Deficits in Children: Preliminary Findings". Journal of the American Academy of Audiology 22 (10): 678–96. doi:10.3766/jaaa.22.10.6. PMID 22212767.
- Leite RA, Wertzner HF, Matas CG (2010). "Long latency auditory evoked potentials in children with phonological disorder". Pró-fono : Revista De Atualização Científica 22 (4): 561–6. doi:10.1590/s0104-56872010000400034. PMID 21271117.
- Mudford OC, Cullen C (2004). "Auditory integration training: a critical review". In Jacobson JW, Foxx RM, Mulick JA (eds.). Controversial Therapies for Developmental Disabilities. Routledge. pp. 351–62. ISBN 0-8058-4192-X.
- Auditory processing disorder: An overview for the clinician
- American Speech-Language-Hearing Association (ASHA)
- UK Medical Research Council Institute of Hearing Research)
- Auditory Processing Disorder in the UK (APDUK)
- Support community for CAPD