[Dtb-talk] Converting tone indexed books to DAISY

[Greg Kearney]

I have been experimenting with the process of converting a tone  
indexed tape book such as those from the National Library Service into  
DAISY setting the navigation at the indexed points. Here is what I am  
doing.

Hardware: For the playback I am using a standard NLS C-1 tape player.  
I am recoding into an Apple Macintosh computer using an iMic USB audio  
interface. I patch between the AUX out port on the player into the  
line in jack of the iMic. I have a Maxstore Firewire drive which is  
used as the scratch disk for the recording software and as the  
location for the audio files.

Software: For software I am using Sound Studio 2.5. This software will  
record to disk in the background. It will also let me stretch out the  
sound, apply filter to reduce the tape hiss and most importantly mark   
and then split the recording at the marked points.

Process:

1. Record each side of the book into a AIFF file at 1 7/8 speed. This  
is twice the normal payback speed and each track records at about 1  
hour. The recoding is done as Mono as there is no stereo information  
coming from the playback device.

2. Once the recording is finished I apply filter to reduce hiss and  
then "stretch" the recoding by changing the sample rate to twice the  
time as the original recording as it was recorded at 2X speed. I now  
have a normal speed audio file.

3. Tone indexing appears as a low frequency signal just before the  
start of the content on the visual display of the recording. I simply  
scroll through the recording looking for this distinctive visual  
signature. (I'm a dyslexic so looking for the visual signature is  
simple for me.)

4. At the point just beyond the index tone I place a marker using the  
marker function of the Sound Studio software. I also name the marker a  
meaningful name such as contents, preface, chapter 1 and so on.

5. Once the marker are set and named I then use Sound Studio to split  
the recording apart at the marker giving me a directory filled with  
recording. I can then use these in my DTBmaker program to generate a  
DAISY DTB  using the set of recording.

I could improve this process by having a player that could play at 3X  
or 4X speed which would quicken the production. However I know of no  
such device. It would be interesting to see if there were a way for  
the computer to detect the index tones and mark the file. Then you  
would only need to check that the markers were in the right places in  
the file. This would permit the blind to do the conversion process as  
well. Further it would be useful if the National Library Service had  
tone indexed their book at the page level rather than just at the  
chapters. The DAISY book I was able to produce with this method is  
navigable to the chapter only.

Greg Kearney
Wyoming Medical Center
307-577-2473