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Re: NISO/DAISY on Audio Playback Controls

From: Jon Gunderson <jongund@ux1.cso.uiuc.edu>
Date: Thu, 30 Nov 2000 10:47:10 -0600
Message-Id: <>
To: Harvey Bingham <hbingham@ACM.org>, <w3c-wai-ua@w3.org>
In synthesized speech we do not need to worry about pitch restoration, 
since the pitch is generated by the computational filters of the speech 
engine.  We should maybe mention pitch restoration as part of checkpoint 
4.5 as speech is slowed down.


At 01:51 AM 11/30/2000 -0500, Harvey Bingham wrote:
>[HB comments by Harvey Bingham.
>UAAG1.0 does address some of the audio playback issues.
>Many other issues, specific to digital talking books, go beyond what
>UAAG addresses. The intent for playback devices is that these
>capabilities are appropriate for some classes of players, noted by the
>digit-letter codes. Players: 1=basic, 2=advanced, 3=computer-based;
>feature: A=essential, B=highly desirable, C=useful.]
>Playback Device Guidelines for Digital Talking Books
>Prioritized List of Features for Digital Talking Book Playback Devices
>      http://www.loc.gov/nls/niso/features.htm
>Version Date: December 30,1999
>[HB The National Information Standards Organization (NISO) is allowed to make
>standards, at least in USA. The international Digital Audio Information
>SYstems (DAISY) Consortium of libraries for the blind and visually
>impaired is developing this as a NISO "standard."]
>3. Audio Characteristics
>3.1 Sound quality (1A, 2A, 3A) (To be quantified)
>Audio material shall be distributed in a form that provides a minimum of 
>FM quality sound to the user. (This section will be expanded, based upon 
>Audio Engineering Society project AES-X74, Recommended Practices for 
>Internet Quality Descriptions.)
>[HB UAAG has nothing comparable.]
>3.2 Volume control (1A, 2A, 3A)
>The user can adjust the volume to meet hearing and listening conditions.
>[HB Checkpoint 4.10, ?4.11]
>3.3 Tone control (1A, 2A, 3B)
>The user can adjust the equalization (the amount of low, mid-range or high 
>frequencies) to suit individual tastes and listening conditions. The 
>device shall include a high-frequency adjustment to compensate for 
>age-related hearing loss.
>[HB No mention.]
>3.4 Variable speed, with pitch restoration (1A, 2A, 3A)
>Playback speed is adjustable over a range from 1/3 to at least 3 times the 
>normal playback speed, and the pitch of the narration is not altered by 
>the speed change. The Time-Scale Modification system shall not produce 
>audible chopping, burble, or reverberation and shall not skip over 
>significant units of sound at high playback speeds.
>[HB 4.12: 120 to 400 words per minute. No mention of pitch restoration.]
>3.5 Pitch restoration control; independent of speed (1B, 2B, 3B)
>Although pitch restoration may be the default, the user can adjust the 
>pitch of the narrator's voice independent of the speed to make it more 
>intelligible at extreme speeds, or to compensate for hearing loss.
>[HB No mention.]
>3.6 Amplitude compression (1C, 2C, 3C)
>Gives the user a method of narrowing the volume range between the quietest 
>and the loudest portions of a talking book. This would be useful when 
>listening to the book at a distance, in a noisy environment, or for a 
>person whose hearing has limited dynamic range. The AC-3 audio compression 
>standard includes this function.
>[HB No mention.]
>3.7 Stereo (3B)
>Could be useful in auditorially displaying spatial arrangements of 
>information, such as matrices in T.V. Raman's ASTER system.
>[HB No mention.]
>3.8 Balance control (stereo) (3A)
>[HB No mention.]
>Regards/Harvey Bingham

Jon Gunderson, Ph.D., ATP
Coordinator of Assistive Communication and Information Technology
Division of Rehabilitation - Education Services
College of Applied Life Studies
University of Illinois at Urbana/Champaign
1207 S. Oak Street, Champaign, IL  61820

Voice: (217) 244-5870
Fax: (217) 333-0248

E-mail: jongund@uiuc.edu

WWW: http://www.staff.uiuc.edu/~jongund
WWW: http://www.w3.org/wai/ua
Received on Thursday, 30 November 2000 11:46:19 UTC

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