Dysarthria, characterized by abnormalities of the articulation and intelligibility of speech, is one of the most recognizable symptoms of ALS.1 It typically starts with a slurring of words and progresses to the point that speech eventually becomes impossible for others to understand. Eventually, most people with ALS rely on communication technologies.

Just how speech is affected varies by individual. Here are some examples of ALS speech symptoms: 2,3,4 

  • Slow, slurred and difficult-to-understand speech
  • Difficulties managing the voice’s pitch, tone and rhythm.
  • Weakened, strained voice
  • Difficulty forming words and pronouncing certain consonants
  • Nasal-sounding voice
  • Hoarseness
  • Decreased range and volume

ALS typically begins one of two ways: as weakness in the limbs, called limb (or spinal) onset, or difficulty in speaking or swallowing, termed bulbar onset.5 Limb onset is the most common, present in about 66% to 75% of ALS patients.6

Dysarthria is an early symptom of bulbar-onset ALS but not of limb-onset ALS. In fact, speech impairment may begin up to three years prior to diagnosis of bulbar-onset ALS, and research suggests artificial intelligence (AI) may be able to detect early, often imperceptible, changes in speech and voice.7

Nevertheless, regardless of ALS type, 80% to 95% of people with ALS will, at some point, no longer be able to be understood with the use of natural speech.8

Attack on Bulbar Neurons and Lung Involvement

ALS leads to speech problems when it attacks bulbar neurons, the nerve cells responsible for bringing messages from the lower parts of the brain (bulbar region) to the muscles of the lips, tongue, soft palate, jaw and voice box. Eventually, the muscles become weak and tight, limiting tongue, lip and/or jaw movement. Bulbar motor deterioration also impairs swallowing, which can lead to a buildup of saliva in the mouth.9

Weakening lung muscles have an effect, too: People with ALS often find speaking to be tiring, and they tend to talk less or in shorter sentences.

Preserving Communication

Perhaps the most important piece of advice is to find a speech therapist or speech-language pathologist familiar with ALS. If you have an ALS diagnosis, do this as early as possible — don’t wait for your speech to be affected. The two of you can work together to develop strategies for maintaining communication. They can help with techniques for projecting your voice and speaking clearly for as long as possible. They can also recommend alternative ways to communicate and help you prepare for when you will no longer be able to talk.10,11

Examples abound: For instance, if you are able to type, many smartphone apps and other devices can convert written words into audible speech. There is also alternative and augmentative communication, known as AAC, which can be used to help the patient communicate more clearly. Other speech-generating devices can be operated with eye or head movements.12 And many people with ALS turn to message and/or voice banking:

Message banking involves recording phrases and expressions that you frequently use. These can include words of affection, terms of endearment, your favorite expressions, greetings, a blessing, an expletive, praise for your pet, etc. Other phrases that may be important are “I use this device to speak, but my thinking and hearing are fine. Please speak directly to me,” and “Wait! I need to say something.” Free message banking apps are available, and your speech therapist can help you find the right one and advise you about microphones and other devices.

Voice banking involves recording your voice in a device called a speech synthesizer. It creates a synthesized voice based on samples of your speech. Again, your speech therapist can help you find the best program for you. Unlike message banking, these can be costly.

15 When you are unable to speak, you can use the speech synthesizer to communicate, and it will, to some degree, sound like your natural voice.

Keeping the Connections

Voice problems associated with ALS make it challenging for people with ALS to communicate their needs to caregivers. It can also diminish quality of life.16 However, it’s possible to preserve communication even when talking becomes impossible. Research shows that communication systems can improve or at least stabilize quality of life and mood in many people with ALS.17



1 Tomik B, Guiloff RJ. Dysarthria in amyotrophic lateral sclerosis: A review. Amyotroph Lateral Scler. 2010;11(1-2):4-15. doi: 10.3109/17482960802379004. PMID: 20184513

2 https://voicefoundation.org/health-science/voice-disorders/voice-disorders/voice-dysfunction-in-neurological-disorders/amyotrophic-lateral-sclerosis/

3 https://www.als.net/news/science-sunday-limb-and-bulbar-onset-als/

4 https://alsnewstoday.com/speech-problems/

5 https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Amyotrophic-Lateral-Sclerosis-ALS-Fact-Sheet/  

6 https://alsnewstoday.com/forms-of-als/

7 Tena A, Claria F, Solsona F, Meister E, Povedano M. Detection of Bulbar Involvement in Patients With Amyotrophic Lateral Sclerosis by Machine Learning Voice Analysis: Diagnostic Decision Support Development Study. JMIR Med Inform. 2021;9(3):e21331. Published 2021 Mar 10. doi:10.2196/21331

8 Brent JR, Franz CK, Coleman JM 3rd, Ajroud-Driss S. ALS: Management Problems. Neurol Clin. 2020;38(3):565-575. doi:10.1016/j.ncl.2020.03.013

9 Green JR, Yunusova Y, Kuruvilla MS, et al. Bulbar and speech motor assessment in ALS: challenges and future directions. Amyotroph Lateral Scler Frontotemporal Degener. 2013;14(7-8):494-500. doi:10.3109/21678421.2013.817585

10 https://my.clevelandclinic.org/health/diseases/16729-amyotrophic-lateral-sclerosis-als

11 https://alsnewstoday.com/speech-problems/

12 https://alstreatment.com/speech-affected-als/

13 https://www.als.org/navigating-als/resources/fyi-suggestions-and-information-about-speech-changes

14 https://alsworldwide.org/care-and-support/article/messagebanking.com-preserve-your-voice meet

15 https://www.mda.org/quest/article/voice-banking-offers-promise-natural-voice

16 Brent 2020 op. cit.

17 Körner, S, et al. Speech therapy and communication device: Impact on quality of life and mood in patients with amyotrophic lateral sclerosis. Amyotrophic lateral sclerosis: official publication of the World Federation of Neurology Research Group on Motor Neuron Diseases. 14. 10.3109/17482968.2012.692382.


Join Us

Keep up with the latest news, events and ways to get involved.

    Join Us