Throughout society there are many people with differing disabilities who for various reasons might struggle with spoken communication. This could include a range of difficulties from mild to profound difficulties, where the person relies on other non-spoken communication methods. The Australian Institute of Health and Welfare in 2009 found 1.3% if the population have difficulty communicating, whilst 16% of the population has difficulties in swallowing. A further 1 in 7 users of disability services (over the age of 5 years of age) “have little to no functional speech” and over 40% require communication assistance. In the United States it has been found that:
- 5% of adults have difficulties seeing words/letters in newsprint (which increases to 10.1% for people aged over 65 years of age)
- 1% of adults have difficulties having their speech understood (which increases to 2.1% for people aged over 65 years of age)
When considering the needs of the people who have difficulty communication by speech, it is also opportune to include those occupants of a building who may not understand visual signage and public audible announcements. This group is considered to include building occupants who may not speak or understand English. It is acknowledged that non-English speaking people may not register the warning triggers during an evacuation and may require additional assistance evacuating a building. He therefore suggests that multi-lingual evacuation messages will benefit the situation, though symbols in internationally recognised designs should also be considered.
With that in mind, there must be some caution shown when developing exit signage using the typical ‘International Symbol of Access’ wheelchair symbol. This could cause confusion between signage identifying the locations of accessible features in a building, such as accessible entrances or accessible toilets.
 People with Disability Australia 2014, Senate Inquiry into the prevalence of different types of speech, language and communication disorders and speech pathology services in Australia Submission February 2014, p.2, http://www.pwd.org.au/documents/pubs/SB140228-SCCASpeechPathologyServices.pdf, viewed 27 August 2015
 Centers for Disease Control and Prevention, Prevalence and Most Common Causes of Disability Among Adults — United States, 2005, http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5816a2.htm, viewed 28 August 2015
 Cameron, CT 2003, Emergency Planning for People With Disabilities and Other Special needs, p.2, http://www.disabilitypreparedness-ncr.net/Emergency%20Planning%20for%20People%20With%20Disabilities%20and%20Other%20Special%20needs%20-%20article%20revised%2005-21-03.pdf, viewed 21 October 2013
 Mandelblit, B 2004, ‘Planning Evacuation for the Disabled’, Security: Solutions for Enterprise Security Leaders, Apr2004, Vol. 41 Issue 4, pp.43-44