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Hello,
I am a phd student at the University of Sheffield and am currently doing
research into finding ways for people to bank their voices and also to be able
to personalise speech synthesisers once their voice has started to deteriorate.
I am using the technique, like that used in speech recognition where people can
adapt synthetic voices to their own using a limited amount of data, as was
suggested in a previous reply, but it is at the moment early in its development
and has not yet been made available for use publicly. I am starting to use it
with standard speech and seeing if there is a possibility of using it with
dysarthric speech and producing an acceptable output. It is currently still a
research tool and is not yet suitable for use with any communication aids,
particularly with its speed of synthesis. Hopefully though this could be an
option for the future for voice banking.
These people in duPont Hospital and University of Delaware have been looking
into this and have some software that you can download to try and build your
own synthetic voice.
http://www.asel.udel.edu/speech/Users-participation.html
I haven't tried this at all though and have just got this information from the
internet so don't know exactly of the quality that you could end up with. It
uses concatenative synthesis which is when you make a large database of
recordings and chop these up into smaller units, such as the individual sounds,
and then recombine them to make new utterances. This tool is a way of
minimising the amount of recording necessary to build a voice by making
recordings and ensuring that these recordings cover all the sounds in a
language and making sure that the recordings are consistent enough with each
other so that when they are concatenated together, there will be less
distortion between the units. However, the recordings that they collect are
likely to be usable ONLY with their own speech synthesiser so may not be the
best way to store the voice long term.
It is possible to build concatenative synthesis voices using software called
Festival and Festvox from CSTR, University of Edinburgh, which is downloadable
from the web but this however involves a lot of knowledge of the synthesis
process and phonetics and is very involved and time consuming. It is designed
to be used as a research tool and there is also no real guarantee that the
output will be reasonable (stated themselves on the website). Again, this
output will only be able to be used with their own speech synthesiser. I have
built voices using this process using professional speakers with 600 sentences
of high quality recordings and the voices are ok but they are not very high
quality consistently and really twice this amount of data is necessary for this
task.
It is quite a difficult task but I think the advice given in the previous email
holds. I am definitely no authority on this but will pass on a few
recommendations that I have used recording voices for my research. If you want
to record your voice to bank it then to keep the options open for future speech
synthesis techniques that will allow you to build your own voice:
1. The recordings should be as high quality as you can get - using a
non-compressed format (i.e. not mp3 etc.).
2. They should be done either in one go or at the same time of day over a period
of time, don't record if you have a cold etc., basically trying to keep the
recording conditions as consistent as possible.
3. Record words and phrases that you would like to use as much as possible,
including names and places that would come up frequently.
4. Also try and record a set of data that has a wide phonetic coverage of
English. One suggestion is to record set A of the Arctic database which is
around 600 sentences. This was designed to have full coverage of the diphones
(a usual base of unit size for concatenative synthesis) of English specifically
for a speech synthesis task. This can be found at
http://festvox.org/cmu_arctic/
by clicking on the cmu_data file.
I hope this helps, please let me know if anything above is unclear.
All the best
Sarah Creer
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Clinical Applications of Speech Technology
Departments of Computer Science and Human Communication Sciences
University of Sheffield
[log in to unmask]
www.dcs.shef.ac.uk/~sarahc
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