Sound

Sound is increasingly being used to convey information important to the computer operator. This includes alerts in addition to speech and other complex audio feedback. This can pose problems for any user on an airplane or in other noisy environments, and it especially can cause problems for those who are deaf or hard of hearing.

Hardware design strategies for providing greater access to aural information include the following:

1.Provide a headphone jack.

Headphone jacks allow users with reduced hearing to block out background noise and make the output louder (by using headphones or by connecting directly to their hearing aids).


  1. Maximize the range of volume adjustment.

    Volume controls allow users with reduced hearing to adjust the volume level to suit their needs.


    3.Direct speakers toward the user.

    This maximizes the signal-to-noise ratio (SNR) for all users. This is especially important for users with hearing loss.


    4.Provide a visually distinct indicator for all alerts or warning sounds created by hardware.

    Visual indicators make recognizing alerts easier for users working in loud environments or for users with deafness or reduced hearing. (Software-generated alerts should be handled by software.)


    5.Provide a visual indication of important sounds generated in normal computer operation.

    Some natural sounds, such as those generated by a disk drive or printer, can be important to system operation. Where this is true, some visual indication of the sound should be provided so users in loud environments or those with reduced hearing or deafness can effectively use the systems.


    6.Send hardware-generated beeps to the operating system.

    This allows visual display of beeps for users in loud environments, users located in another room, or users with reduced hearing or deafness. Examples include beeps related to the keyboard and printer.


    7.Place the microphone in the orientation recommended by the microphone manufacturer.

    Along with speech-recognition software, properly locating the microphone makes the computer more accessible to users who are blind, have low vision, are physically disabled (including those with repetitive strain injury [RSI] and carpal tunnel syndrome), or have difficulty writing.


    8.Include a speech-capable sound system.

    Such a sound system provides speech capabilities for nonspeaking persons. It also provides the necessary hardware support for a speech-based access system used by people with low vision, blindness, or reading difficulties.


    9.Reduce noise level of operating internal components.

    This increases the ability of users with neural hearing loss or hearing aids to converse or use computer sound-based features.