Hearing impairment and Deafness are some common issues that impact the usability of audio and multimedia interfaces. Web applications are evolving from being text-based to being multimedia-based, or incorporating both in the same interface.
Hearing impairments could be broadly classified into two categories: deafness (which refers to the complete loss of the ability to hear from one or both ears) and hard of hearing (which refers to partial loss of the ability to hear from one or both ears). The level of impairment could be mild, moderate, severe, or profound.
Captioning is one way of solving difficulties that are faced by deaf or hard of hearing users. Captioning provides textual representation of spoken/audible content on video, DVD, and film media. It is usually displayed along the bottom of the viewing screen.
This ADE will provide you with some insight and experience to the accessibility difficulties faced by those who are Deaf and those who are hard of hearing. The videos and sound clips in this ADE will illustrate some of these issues.
The following video will introduce you to life with limited hearing:
Listen to each one of these short sound clips. Each is part of a sound clip that discusses the effects of loud noise in any working environment. The clips illustrate some of the issues of hard of hearing. The audio clips used in this section are from audio demonstration of noise induced hearing loss.
Most visual impaired users can hear audio sounds played faster than the average person. This sound clip illustrates the difficulties that would be faced by hard of hearing users if they attended a presentation for those with visual impairment. Note that users with visual impairments have higher hearing ability and could hear audio at higher speeds with comfort. Here is a sample audio clip at high speed: High Speed Audio Clip.
Now listen to the High Speed Activity Audio Clip and type what you hear in the text area provided. When you are finished, click Submit to check your accuracy.
Another issue that affects hard of hearing users is muffled audio output accompanied with noise. This audio clip illustrates this issue. Listen to Muffled Audio Clip.
Now listen to the Muffled Activity Audio Clip and type what you hear in the text area provided. When you are finished, click Submit to check your accuracy.
The use of low volume and unclear audio output creates another issue for those with hard of hearing. The next audio clip illustrates this issue. Listen to Low Volume Audio Clip.
Now listen to the Low Volume Activity Audio Clip and type what you hear in the text area provided. When you are finished, click Submit to check your accuracy.
Captions can be used to solve most of the issues affecting hard of hearing users. This clip illustrates how captions can be useful them in accessing audio content. Effects of noise audio clip.
The video clips provided in this section illustrate some of the issues related to captioning. Pay attention to how captions are implemented in each of these video clips. The video clips used in this section are from NOAA PMEL Vents Program
The captions provided in videos on the web should be of the correct font size and type such that it is readable by the user. Synchronization of the captions with the audio output also affects the readability of the captions. The following video clip illustrates these issues: Font and Synchronization Video Clip.
Some captions are designed for high resolution screens. When they are viewed using low resolution screens, the content may become inaccessible. This issue is illustrated in the Rendering Space Video clip.
Type what you read in the Rendering Space Video Clip in the text area provided. When you are finished, click Submit to check your accuracy.
As noted in the Secondary Encoding and Assisting Vision - Using Colour Shifting and Shading ADEs, using contrasting colours is important to the accessiblity of web sites. The same could be said about captions. The next clip illustrates this issue of colour contrast. Watch the Colour Contrast Video Clip.
For some people, reading text written in uppercase is not an easy task and would prefer the use of mixed upper and lower case captions. However, reading captioning in lower case can also create problems as letters such as p, q, g, and y must be written in a higher position than normal. For example, the letter g could be mistaken for a 9. The following video will illustrate the issue of using only uppercase letters. Using Uppercase Video Clip.
Watch the video provided on iCommunicator. This is one way of providing captions.
It is encouraged that you explore and learn to use MAGpie at Captioning with MAGpie 2.0 to make your videos clips and captioning.
For Hard of Hearing Issues:
For Captioning Issues: