Hearing & speech development

Hearing is the perception (or awareness through the senses) of sound. We humans can hear frequencies from 20 to 20,000 Hz but we do not always use our full range of hearing, especially frequencies above 8,000 Hz, as these are rare and not used in speech. Our ability to hear allows us to discern the pitch, loudness and direction of sounds.

Pitch is the perception of frequency and we are able to discriminate between frequencies. In music, notes are given names, and someone who can identify a note by hearing it and reproduce it by reading it, has what is called perfect pitch.

Loudness is the perception of intensity of a sound and we can distinguish between a change of a few decibels of loudness, but this perception has a strong relationship to the frequency of the sound heard. We have a maximum sensitivity to frequencies of 2,000 – 5,000 Hz, which means that sounds in this band are perceived to be louder than sounds above or below this range.

Hearing and speech development

To develop language, speech and communication skills, a child needs exposure to sound, to be able to develop listening skills and to have the ability to hear (through intact physical structures) and to process/interpret the sounds heard.

Hearing loss and/or auditory processing issues affects not only language development but the ability to learn to read and write and to develop social skills.

Hearing loss may be temporary during a nasty cold or upper respiratory infection but, in those children with chronic middle ear infections or repeated ear infections, it has now been confirmed that their experienced reduction in hearing can affect language development in the auditory cortex.

Development of the auditory processing centres requires stimulation and is at its greatest when a child is young, hence the exponential growth in vocabulary between 12 and 24 months of age.