Auditory perceptual learning and training

Auditory training, like physical training, involves practice. It is usually achieved by playing special computer games that require the listener to make judgements between similar sounds. The resulting auditory learning might be able to help children and older people improve their ability to listen by processing sounds efficiently. For those with hearing loss and other listening problems, auditory learning has the potential to be particularly useful. People using hearing aids and cochlear implants may also learn to use those instruments more quickly, and to achieve better outcomes in the longer term. Our research has shown that the benefits of training depend not only on the task or sound being trained, but also on the ability to attend to and memorize sound. Attention is probably the most important of these skills. If improved, it is likely to benefit not only a wide range of listening abilities, but more general mental skills, for example in older people. To see how training affects sound processing in the brain, we use techniques including measures of brain electrical (EEG) and magnetic (fMRI) activity before, during and after learning.

The way we perceive the auditory world changes throughout life with development, experience and training. The peripheral auditory system reaches maturation early on in development, but the way in which the brain processes the input from the peripheral system changes dramatically throughout life. Auditory perception is dependent not only on the ability to hear sounds but also on the ability to process them efficiently. The aim of this strand is to investigate auditory learning with an emphasis on both the underlying mechanisms and translational potential.

Our findings so far provide converging evidence that auditory perception and learning depend heavily on cognitive factors such as attention, working memory and general IQ. Our most recent studies with normally hearing adults have provided evidence that improvement in auditory perceptual tasks at least partially depends on improved working memory for sound and the ability to attend to a task, even if it is not auditory (e.g. Tetris or Sudoku). Performance feedback affects learning, but different people are affected in different ways, depending on their IQ and naove auditory processing abilities, highlighting the need for an individualised approach to training. In typically developing children we have shown that training in a school environment improves ability to train for longer and achieve better results. Training is variable - some children can achieve adult-like thresholds with training, while others cannot - this ability depends on an interaction between age, IQ and the ability to attend to the sounds through the testing period. Training in simple acoustic stimuli was also shown to generalise to broader language measures of phonological awareness, which is a precursor for literacy.

Thus, aspects of cognition, and in particular top-down attention mechanisms, appear to be more important than bottom-up channel sharpening in the ability to improve perception through training. We are now planning to investigate what is the optimal number of training sessions, amount of training per session and content of sessions for adults and children. This will enable us to take training further in the hope of improving perceptual skills not only in children with auditory and language-learning disorders but also hearing impaired individuals and cochlear implant users. We will also seek the neural origins of learning in imaging studies of the brains of individuals as they learn.