It is an accepted fact that the younger the child, the easier it is for them to learn a second language.
Children are able to understand words and hear small sound differences that adults often miss -- making understanding more difficult for adults.
For example, Polish students of English have difficulty differentiating between vowels such as "pen" and "pan" while German students must learn to hear a difference between the v in "vest" and the w in "west".
Scientists used to believe that the adult brain could not be retrained later in life to distinguish between these sounds: in other words the brain's plasticity (or ability to change) was set.
Scientists now believe that the difficulties are caused by our experience which teaches us to ignore certain sounds so that we are able to give our full attention to the sounds that (in our native language) matter most to understanding a sentence.
Two studies jointly worked on by Dr Paul Iverson and Dr Valerie Hazan, UCL's Department of Phonetics and Linguistics, have examined whether it is possible to retune how the brain processes speech sounds, and hope that their findings will help make language learning easier for adults.
In one study, Japanese subjects were retrained to hear the difference between r's and l's (something that Japanese students of English tend to find particularly difficult).
Similar tests were carried out in London on Sinhalese (from Sri Lanka) and German speakers who had lived in the UK for more than 20 years.
Talking at the UCL workshop, which brings together specialists in language, speech and speech perception, Dr Iverson said: "Adult learning does not appear to become difficult because of a change in neural plasticity.