Normally, children master speech skill by seven years of age but, sometimes children are born with an oral-facial malformation such as cleft of lip and/ or prosthesis. Certain residual difficulty in maintaining air pressure in the mouth results in misarticulation and nasality. Lesions to some centres in the brain cause weakness, incoordination and paralysis resulting in a speech disorder called dysarthria. Also, there are some children with intact speech organs who find it difficult to say some speech sounds. By using speech therapy techniques, it is possible to improve the clarity of their speech.

Abuse, misuse, structural abnormalities such as growth on the vocal voice, persistent hoarseness may be an early sign of laryngeal cancer. Voice therapy can restore or maintain one’s voice.

Disruption of the flow of speech reduces its effectiveness and is known as stuttering or stammering. This may range from mild hesitation to a severe disruption in the flow of speech. Such people not only need prompt therapeutic intervention but also support from family and friends.

Damage to the speech centers (for example in stroke patients) cause language disorder known as aphasia. Such people have difficulty in expressing and understanding speech. In addition, they may have difficulty in reading, writing and calculating. Speech and language therapy helps to recover their speech communication skills.

Various diseases such as lesions in the brain (e.g. stroke), supraglottic tumors, traumatic brain injury, degenerative diseases, cerebral palsy, chemotherapy patients, laryngectomy, tracheostomy, and clefts result in swallowing disorders (dysphagia). Compensatory and therapeutic techniques are carried out to improve swallowing.

Although the hearing impaired child has the ability to speak, he can neither hear what he has to produce nor correct his poor imitations. Such children need immediate audiological help to find out how much of the child’s hearing ability has been left intact. Depending upon whether the hearing loss is mild, moderate, severe or profound, a hearing aid has to be fitted. A hearing aid or cochlear implant helps the child hear better and auditory training is important for listening. Speech and language stimulation helps the child to step into a talking world and learn more about it. Hearing loss can also occur after we learn to speak.
Depending upon its severity, it can not only disrupt listening to other’s speech but also one’s own speech.