Volume is a key component in processing sound. How loud or soft is the sound? How does the volume change across time as we listen?
Changes in volume occur naturally with sound, whether this is music, speech or other environmental sounds. We know if a car is coming towards us as the volume will increase as it moves closer. This type of clue is important for keeping us safe.
In terms of speech, an individual speech sound, known as a phoneme, changes in volume as it is produced by the mouth. Some sounds like ‘t’, ‘b’ and others hit a peak of volume quickly and then fade quickly. Other vowel sounds take longer to reach a peak of volume. This is known as rise time. This also happens with different instruments; think of the difference in sound between a percussive instrument such as a piano with the same note that may be produced on a cello. The cello has a much longer rise time. You can see below how the second sound takes longer to reach a maximum volume and then reduces more slowly.
It is well understood that many people with auditory processing and reading problems, as well as dyslexia, have challenges with processing these very small changes in volume. This is discussed in more depth by Usha Goswami from Cambridge University. She also helps us understand how important amplitude or volume modulation is for understanding the social aspects of language as well as reading and listening in general.
A large body of research such as Hornickel & Kraus (2013) confirms that sound reaching the ear is not always represented faithfully in the brain. This means our hearing is good, but our listening is impaired as the sound is not transmitted to higher areas of the brain effectively. You can understand how difficult this is for children in the classroom to listen if there is any noise in the background. They are already having to work twice as hard as their peers to be able to listen to, and process, what is being said. It is well understood that for anyone with a diagnosis of Auditory Processing Disorder, Dyslexia, Autism or reading difficulties they are likely to have challenges with the processing of volume.
Do you know anyone who misinterprets what is being said and often thinks they are being ‘told off’ when they are just being given guidance or instructions?
Do you know anyone who thinks their friends don’t like them because of something they said?
Do you know anyone who finds it difficult to listen in any background noise or needs lots of repetition?
These are clear signs of a difficulty with processing changing volume. This happens over milliseconds and is very subtle.
As discussed in the previous blog on frequency and speech, music, singing, reading out loud and encouraging active listening can help to develop these skills. Discussing how sounds change in the environment can improve attention. An example of this may be explaining how a car coming closer gets louder or how volume changes in birdsong that you are listening to.
The Listening Program uses very specific techniques to train volume awareness. These include modulating the volume of individual instruments as well as a technique called audio bursting. This is when the volume is increased and decreased quickly on an instrument to help train auditory attention.
The brain can be retrained to improve volume awareness. This can have a very positive impact on many areas from social understanding to reading and listening improvements. Working at the most basic levels of auditory processing naturally feeds through to the higher levels of listening and attention and should be considered for anyone with these problems.
Alan Heath is the Director of Learning Solutions and International Representative for Advanced Brain Technologies. He is the co-developer of The Movement Program and TAVS (Test of Auditory and Visual Skills)
Hornickel, J. and Kraus N. (2013) Unstable Representation of Sound: A Biological Marker of Dyslexia. The Journal of Neuroscience, February 20, 2013 • 33(8):3500 –3504 https://doi.org/10.1523/JNEUROSCI.4205-12.2013