Speech Generation Using a Neural Network NetTalk Project Speech Generation Using a Neural Network Michael J Euhardy

The Speech Generation Idea Input: a specific letter whose sound is to be generated Input: three letters on each side of it for a total of seven letters input Output: the sound that should be generated based on the input letter and the surrounding letters

The Strategy 26 possible letters 7 input position Map each letter in each position to a unique input 7*26 = 182 total inputs

The Strategy 57 possible sounds generated Map to 57 output labels

The Resulting ANN A fully connected single layer perceptron with 182 inputs and 57 outputs

The Findings The trained neural network performs very well, and the larger the training set and the longer spent training on it, the better it performs The training can be an extremely long process if a high rate of classification is desired and the training set is large

Problems Time Space

Time You can’t rush training the network. Even using a dual PIII-733 with 512MB, it still took a really long time to train any data of a significant size. And just converting all of the characters in the data file to the matrices necessary to use as inputs and labels took hours.

Space 20000 words of data with maybe 7 letters on average. That’s a matrix 140000x239 Double precision in Matlab, that’s a lot of memory

Workarounds Smaller data set, only 1000 words Lower standards of training, only train to 80% classification

Next Time C++ Start Earlier, it’s a long process Matlab is way too slow and way too memory intensive Start Earlier, it’s a long process Multi-Layer Perceptron

Conclusion I give up! I don’t know how Microsoft’s Narrator does it, but I bet it doesn’t do it this way.