In general, audio menus should not contain more than a few items;
recommended maximums are described in Table 1. There might be times when
you have no choice but to present a list of more than the recommended
number of items. If so, a good way to manage the list may be by using
a “speak to select” strategy or list-scanning commands.
Using a “speak
to select” strategy
When presented with a running list
of items, users (even first-time users) typically say one of a small
number of phrases to interrupt the list when they hear the item they
want, including utterances such as “OK”, “Stop”, or “Yes”, or simply
repeating the target item. For example:
| System: |
When you hear the name of the desired video, please repeat it:
The Maltese Falcon
Gone with the Wind
The Nutty Professor
The War of the Worlds
|
| User: |
Yes.
|
| System: |
Adding “The War of the Worlds” to your shopping cart.
|
|
Note: The prompt still suggests that the user repeat the
desired movie name (rather than just saying “yes') because this strategy
takes some of the time pressure off the user. The user can choose
an item even after several additional selections have been read.
Using list-scanning
commands
For very long lists, you may want to consider
providing list-scanning commands that permit bi-directional navigation,
such as BACKWARD, FORWARD, NEXT, PREVIOUS, TOP, and BOTTOM.
Unless
you have previously identified that the user has experience with the
system, you should plan to announce these list-scanning commands before
presenting the list. You may also want to consider using special audio
tones as feedback for the recognition some of these commands. For
example:
| User: |
List the stocks in my portfolio.
|
| System: |
Your portfolio has fifty stocks. You can use the commands FORWARD, BACKWARD,
NEXT, PREVIOUS, TOP and BOTTOM to control the playback of this list.
General Motors
IBM
General Mills
Hannaford Brothers
Eastman Kodak
|
| User: |
Backward.
|
| System: |
(backward tone)
Eastman Kodak
Hannaford Brothers
General Mills
|
| User: |
Forward.
|
| System: |
(forward tone)
General Mills
Hannaford Brothers
|
| User: |
Price.
|
| System: |
The current price for Hannaford Brothers is 25 7/8, up 1/8.
|
| User: |
Next.
|
| System: |
The current price for General Mills is 87 3/4, down 1/4.
|
| User: |
Bottom.
|
| System: |
(bottom tone)
The current price for Wal-Mart Stores Inc. is 54, unchanged.
|
| User: |
Backward.
|
| System: |
(backward tone)
Wal-Mart Stores Inc.
Kellogg Company
Monsanto Company
(etc.)
|
|