auditory processing disorders

This is a warning that this post is a full-fledged mega academic geek out, and to avert your attention/time to something more frivolous, like cute pug dogs nestled with baby kittens, if you don’t want to spend the next few minutes reading about research.

This is a disclaimer advising that the opinions in this post are my own and information is gathered from peer-reviewed journals (where possible), as well as articles that have academic standing. Please slap me across the wrist if you find that this information cannot be backed up by properly controlled research designs and evidence, and I’ll happily do more investigating of my own. If you would like any further information or articles about this post, send me an email or post a comment.

As a SLP (speech-language pathologist), one comment that irks and grinds me is this, “Oh, so you just fix stutters, right?”. Yup, just like optometrists “just give you glasses”, or audiologists “just fit hearing aids”, or physiotherapists “just massage you”. GAH! I will probably be defending my career choice for the rest of my life, so I’m not as annoyed anymore when people say this to me. (To set the record straight, these are the areas that SLPs can assess and treat: speech, language (including literacy), voice, fluency (i.e. stuttering), swallowing/feeding, and augmentative/alternative communication (e.g. speech-generating devices like the one Steven Hawking uses). And we can work in these areas in the paediatric or adult populations, such as schools, hospitals, private practices, etc., so why is it so hard to find a job? Well, that’s for another post!) What annoys me is people’s ignorance comes across as insulting, and that isn’t just with people outside of my profession, but also within it (unfortunately).

My interests in the SLP field are reading disorders, pragmatics and mental health, all of which can occur in isolation or comorbidly in any of the populations we treat. I also have strong ties to audiology networks and this heavily influences how I manage and treat my clients/patients. I have a very strong interest in auditory processing disorders, which is also known by several other terms, but is a field that has received much critique and contention in both the SLP and audiology realms. Below is an excerpt from a paper (sans referencing) I wrote about whether phonemic awareness intervention helps children read.

Some terms to help you understand:

  • phonological awareness (PA) is a metalinguistic skill which refers to an individual’s ability to reflect upon and manipulate the sound structure of spoken words.
  • phonemic awareness is the ability to manipulate smaller phonological units or phonemes in spoken words, and is a subskill of phonological awareness
  • phoneme is the smallest meaningful unit in a language
  • phonological representation is the mental representation of a sound or combination of sounds that make up words in spoken language

A relatively new area of research is beginning to investigate auditory processing disorders (APD). APD is a sensory processing deficit where children have the inability to discriminate, recognise and understand auditory information – for lack of a better description, “what you do with what you hear”. This has considerable implications for comprehension, language and learning. The test battery for most APD assessments includes a phonemic awareness component (e.g. synthesis and analysis tasks). The rationale for this is that being unable to process speech patterns may result in unclear phonological representations, which in turn could impair phonological awareness, and may compromise normal development of reading abilities. In other words, if a child is unable to hear the phonemes in words, she/he is unlikely to be able to manipulate them, and may struggle in relating these sounds to letter representations in order to accurately and efficiently decode words.

At present, there is no established protocol in specific intervention methods for children with APD. Most diagnostic audiology clinics usually refer these children to SLPs for phonological awareness intervention, who as a profession, also have to establish best practice protocols on as yet to be researched avenues. The research in APD brings to light another level of complexity to children’s learning to read. Children with APD may present like a child who has a hearing loss, and despite having normal development and intelligence, still struggle in learning and reading. There is little research on interventions for APD, and those that have investigated effects of phonological awareness programmes have yielded mixed results in improving children’s reading abilities.

Training in phonemic awareness has yielded positive outcomes for children who have speech/language and reading difficulties. Despite this, some caution needs to be taken when interpreting results. Given that phonemic awareness is also considered a metacognitive skill, there is no denying its reciprocal relationship with cognition when addressing development of reading skills. Research experiments warrant a level of control on experimental variables (e.g. individual differences between groups, matching on age and reading level), and as such, interpretation of phonemic awareness training come out of “ideal” environments.

The counterarguments are aplenty in this field of research but I’m not going to talk about any of those, although the main point of contention is whether APD actually exists at all. My stance on this topic is that it does, it’s relevant (albeit with mixed treatment results) in the SLP and audiology fields, and there really shouldn’t be this “war” over it. How else do you explain what you do with what you hear?

So this blog post was actually sparked on by this current study conducted by UCSF on how the brain sorts out auditory information. There’s a part of our brain called Wernicke’s area, which is, to put it very simply, where information is processed for us to be able to understand. It’s the part of the brain that can usually be affected after a stroke, and is also important for processing auditory information. Basically the research paper investigated participants’ abilities to organise the sounds of the language in our brain, and has some amazing implications for how learning processes occur. Although the study itself only used 6 participants (small sample size), I’m still seriously intrigued by this research! More evidence to support areas such as APD! And reading disorders and how we can better shape our interventions! This can only mean more knowledge to generate innovative ideas! Here’s another exclamation mark to mark my excitement!

If you’ve managed to come this far, thanks for sparing some time to read about my professional/academic pursuits :)

dm