The VoxForge phoneset is derived from the CMU phone set (cmudict-0.7b) as follows:

The current phoneme set has 39 phonemes

        Phoneme Example Translation
        ------- ------- -----------
        AA	odd     AA D
        AE	at	AE T
        AH	hut	HH AH T
        AO	ought	AO T
        AW	cow	K AW
        AY	hide	HH AY D
        B 	be	B IY
        CH	cheese	CH IY Z
        D 	dee	D IY
        DH	thee	DH IY
        EH	Ed	EH D
        ER	hurt	HH ER T
        EY	ate	EY T
        F 	fee	F IY
        G 	green	G R IY N
        HH	he	HH IY
        IH	it	IH T
        IY	eat	IY T
        JH	gee	JH IY
        K 	key	K IY
        L 	lee	L IY
        M 	me	M IY
        N 	knee	N IY
        NG	ping	P IH NG
        OW	oat	OW T
        OY	toy	T OY
        P 	pee	P IY
        R 	read	R IY D
        S 	sea	S IY
        SH	she	SH IY
        T 	tea	T IY
        TH	theta	TH EY T AH
        UH	hood	HH UH D
        UW	two	T UW
        V 	vee	V IY
        W 	we	W IY
        Y 	yield	Y IY L D
        Z 	zee	Z IY
        ZH	seizure	S IY ZH ER