Numbers, Spoken in English

Here is a collection of spoken digits as mp3 files, and a program, that will speak numbers up to 1 billion in a female voice. It will speak them either as an English speaker would, or one digit at a time, or as a decimal number.
One.
Two.
Three.
Four.
Five.
Six
Seven.
Eight.
Nine.
Ten.
Eleven.
Twelve.
Thirteen.
Fourteen.
Fifteen.
Sixteen.
Seventeen.
Eighteen.
Nineteen.
Twenty.
Thirty.
Forty.
Fifty.
Sixty.
Seventy.
Eighty.
Ninety.
Hundred.
Thousand.
Million.
Point.
Minus.

The program is written in Processing and uses the Sound library.
Numbers.pde source code.
The function speakNumber(i) will say the given integer in English.
The function listNumbers(i) will say the numbers that are components of i in English in the right order. Can be negative.
The function speakfloat(x) will say the given real number in English. Can be negative.