Definition and Overview

Speech aids, also known as speech-generating devices or voice output communication aids, are electronic devices or entire systems which goal is to support people with speech impairments to communicate verbally despite their condition.

Speech aids come in many different types, ranging from simpler devices to complete systems that allow even emotional information to get through with the help of digitally recording the patients’ natural voices. The effectiveness of speech aids is well-advertised through the personal use and experiences of well-known individuals, one of whom is Stephen Hawking.

Who Should Undergo and Expected Results

Speech aids are prescribed for those who are verbally impaired. Speech impairment may occur due to many possible causes, such as:

  • Stomach acid reflux
  • Throat tumors and cancers
  • Head and neck cancers
  • Polyps, nodules, cysts, and other benign growths on the vocal cords
  • Palate problems, such as cleft palate
  • Nerve damage in the vocal cords
  • Vocal cords overuse
  • Aphasia
  • Verbal apraxia
  • ALS or amyotrophic lateral sclerosis, a degenerative neurological condition that progressively attacks the nerve cells located in the spinal cord and in the brain
  • Birth defects
  • Laryngeal webs, or a thin piece of tissue lodged between the vocal cords
  • Cerebral palsy
  • Speech disorders

Speech disorders, which typically begin at childhood, include:

  • Articulation problems
  • Disfluencies, such as stuttering
  • Language disorders

Most doctors prescribe speech aids when a speech disorder is diagnosed, based on a person’s symptoms, which typically include the following:

  • Stuttering that occurs even when the child is already past the age of 4 years old
  • Inserting extra unnecessary sounds or words in between words
  • Extending the sounds of short words
  • Feeling or seeming frustrated at failing to communicate properly
  • Unusual blinking during speech
  • Jerking the head during speech
  • Being embarrassed to talk
  • Distortion of sounds
  • Substitution of consonants
  • Articulation errors that hinder successful communication

Disorders affecting the voice may have different symptoms, such as:

  • Hoarse voice
  • Rough, raspy voice
  • Sudden pitch changes
  • Voices that are either too soft or too loud
  • Shortness of breath during speech
  • Hypernasality
  • Hyponasality

Many of these speech and vocal disorders tend to resolve over time without treatment, except for those that are caused by diseases. If symptoms are more severe, most doctors prescribe speech therapy first before using speech aids. In many cases, especially when the patient is a child, speech therapy often works; prognosis is especially good if the problem is caught early. However, if the condition does not seem to improve with therapy, this is when speech-generating devices may be used. These devices are expected to completely replace the person’s speech.

Aside from replacing natural speech, speech-generating devices, especially more developed ones, may also be customized to include other capabilities, depending on the needs of the patient.

How Does the Procedure Work?

Prior to the prescription of a speech aid, a person first undergoes several tests to diagnose the specific speech disorder he or she is suffering from. The usual tests used for this purpose include the Early Language Milestone Scale (done on children), the Denver Articulation Screening Exam (which comes in two parts), and the Peabody Picture Test. Sometimes, a supplementary hearing test is also conducted to check for a relationship between speech and hearing issues.

Speech aids typically contain a specific amount of content, which may vary in both quantity and organization depending on the needs of the user. Mostly, however, emphasis is placed on vocabulary items that are versatile, useful in everyday correspondence and can thus be used frequently and in different contexts to give them high functionality and value to the user. However, continuous research is being done in order to increasingly build the vocabulary of speech generating devices as well as improve the speech production rating.

The content, however, is released through either digitized speech or synthesized speech, which are two different output techniques used by speech aids.

Digitized speech refers to speech generating systems that simply play words and phrases that are directly recorded then stored on the electronic device. Since the words and phrases are recorded, they often sound more natural and may be able to convey emotional messages. The words and phrases are often recorded by individuals who are the same age and gender as the intended user of the device. But while this allows a natural-sounding communication, digitized speech greatly limits the number of messages the device can deliver depending on how many words and phrases are recorded and can be stored on the device.

Synthesized speech, on the other hand, is equipped with a translating system that can convert the user’s written message into verbal speech. This allows users to create any string of words or messages and even use different languages, pitch, gender, tone, speech rate, and pronunciations; even pauses and stresses are recognized. Message creation is often done through a combination of written words and phrases or with the use of pictures and symbols. Since there are no storage limitations, this option offers users more flexibility in terms of their verbal communication capacity.

Possible Risks and Complications

The following are the complications that speech aid users face when using these devices:

  • Limitations in their ability to express what they really mean
  • Content selection, especially with digitized speech
  • Storage issues, also for digitized speech systems
  • Content maintenance or the lack of means to add new content, such as names of new acquaintances, to the system if necessary
  • User privacy is compromised in the selection and maintenance of content

Also, it is important for patients to have the right expectations for their speech aids. These devices are not designed to meet every communication need, although efforts are being taken so that they can sufficiently address as many needs as possible.

Another possible risk is when the device is used too early, thus further inhibiting the child’s potential for speech development.

Furthermore, not all speech-generating devices are the same, so it is important for a person to look for a device that is most appropriate for his or her specific needs. There is no single device that is a perfect match for all patients. Usually, patients have to try different types before finding the one that best meets their needs.


  • American Speech-Language-Hearing Association --
  • National Institute on Deafness and Other Communication Disorders --
  • Alexander Graham Bell Association for the Deaf and Hard of Hearing --
  • U.S. Centers for Disease Control and Prevention --
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