Auditory Processing Disorder: when you can’t hear well in noise

Posted by Anna Pugh on Jan 28, 2020 10:19:35 AM

As a Hearing Therapist Audiologist working in the UK private sector, I am very aware that there are many people who experience difficulty in hearing well. But for this blog, I would like to concentrate on a particular issue: Auditory Processing Disorder.

One significant area where people have difficulties making sense of speech is in loud, competing or complex noise environments. Many of the people who come into my clinics don't say "I can't hear a 3KHz single note at 50dBHL", this is a meaningless sentence to them. What they're likely to say is " I can't hear my wife speaking to me in the car!"

Accuracy in speech comprehension when in competing acoustic ecologies - or hearing well in noisy places - is the major issue for most people. Modern hearing aids have features that include noise reduction and directional listening but are designed to focus on the person in front of you, with them only being a few feet away. They don't do the same job as the brain in making sense of speech sounds and cannot replace the damage to your hearing, so they are always limited in their ability to enhance speech clarity in noisy environments.

However, there are people who don't have a clinical hearing loss and so are unlikely to be issued with hearing aids. Therefore, the technology to help with focusing on speech in noisy places is not available to them.

This group of people has more complicated difficulties in terms of recognising and understanding speech sounds. And they often have no clinical hearing loss.

A standard hearing test of single beeps in a sound-treated booth does not show any significant hearing loss within normalised expected parameters or limits in the clinical test, or not enough of a hearing loss to explain the difficulties experienced by the person. We call this Auditory Processing Disorder, or APD. 

This means that the sound signal is received through the hearing mechanisms, but the cognitive function in the brain which controls memory, speech, and hearing finds it difficult to untangle the information received. It is generally accepted by researchers, academics, and practitioners that there are three main groups of people who experience APD, and experience it in different ways:

  • Developmental APD: children who have no other contributing factors suggesting hearing or listening problems.
  • Acquired APD: this happens due to a brain injury like a stroke, or an accident, or some other similar event. 
  • Secondary APD: these people may have a hearing loss, but also have more significant difficulty hearing well than the impact of their hearing loss would suggest.

The British Society of Audiology, who are our professional body for practice guidance, recently reported that these people often experience "…greater difficulty hearing in noise, mishearing speech, frequent requests for repetition, and poor attention to and/or memory of auditory instructions… (yet)... these individuals are currently not well supported in the UK."Whilst a full diagnosis of APD will require specialist cognitive and hearing function tests to determine the degree and nature of the problem, speech in noise tests, word list tests and phoneme tests (parts of a speech sound… like /sh/ or /ch/ and /ahhhh/ or /a/ ), are widely available in audiology clinics, and are part of the standard caseload of Hearing Therapists.

You might ask why it's a problem. Surely mishearing occasionally isn't much of an issue?

Research and anecdotal evidence tells us that children with APD can be labeled as difficult, not bright, disruptive, lazy, awkward. It can adversely affect a child's learning, attention, concentration skills, speech, memory, and self-confidence. These children grow up in adulthood with APD, and with all the consequences of growing up with these negative educational restrictions and a problematic self-image.

Helping people to relearn to listen, and to develop listening skills, is what hearing therapists do. There are various standard Auditory Training Rehabilitation Programmes, both formal and informal.

Formal programmes include speech in noise and phoneme recognition tasks, with questionnaires and exercises where the therapist will score your responses and plan a programme of exercises for you. Some of the less positive aspects of these are that they are mostly non-UK voices, so they don't always address accent or speakers for whom English is not their first language.

Informal programmes use everyday listening environments to practice the skills you learn in therapy. They use speech sounds from the people in your life, or apps and devices to enhance the sounds around you to help you get more information from the world and then to make more sense of it.

Chatable, the Universal Hearing Aid App, can be part of this informal learning. The app reduces the level of competing noise to give you a much better opportunity in getting more of the sound and phoneme information. Chatable enhances the brain's ability to hear speech by providing clear and loud voice without background noise. You may not have APD, you may not have a diagnosis of cognitive hearing difficulties. But if you have difficulty hearing well in noise, I really recommend you try the app to find out what difference it can make to you when listening in real-world environments.

If you would like any information about the research into APD, diagnosis, auditory training and specialist support, or any other information, please feel free to contact me.

Anna Pugh - Hearing therapist and owner of Hearing Therapy Online

For more on Anna, listen to her in these podcast interviews here and here . And you can read about her specialisms here