The settings are explained in frame.h if you download the source code, and I am copying the part of the code that explains the settings below.
// voicing and cascaide
speechPlayer_frameParam_t voicePitch; // fundermental frequency of voice (phonation) in hz
speechPlayer_frameParam_t vibratoPitchOffset; // pitch is offset up or down in fraction of a semitone
speechPlayer_frameParam_t vibratoSpeed; // Speed of vibrato in hz
speechPlayer_frameParam_t voiceTurbulenceAmplitude; // amplitude of voice breathiness from 0 to 1
speechPlayer_frameParam_t glottalOpenQuotient; // fraction between 0 and 1 of a voice cycle that the glottis is open (allows voice turbulance, alters f1...)
speechPlayer_frameParam_t voiceAmplitude; // amplitude of voice (phonation) source between 0 and 1.
speechPlayer_frameParam_t aspirationAmplitude; // amplitude of aspiration (voiceless h, whisper) source between 0 and 1.
speechPlayer_frameParam_t dcf1, dcb1; // change in hz in frequency and bandwidth of cascaide formant 1 in voice cycle while glottis is open
speechPlayer_frameParam_t cf1, cf2, cf3, cf4, cf5, cf6, cfN0, cfNP; // frequencies of standard cascaide formants, nasal (anti) 0 and nasal pole in hz
speechPlayer_frameParam_t cb1, cb2, cb3, cb4, cb5, cb6, cbN0, cbNP; // bandwidths of standard cascaide formants, nasal (anti) 0 and nasal pole in hz
speechPlayer_frameParam_t ca1, ca2, ca3, ca4, ca5, ca6, caN0, caNP; // amplitudes of standard cascaide formants, nasal (anti) 0 and nasal pole in hz
// fricatives and parallel
speechPlayer_frameParam_t fricationAmplitude; // amplitude of frication noise from 0 to 1.
speechPlayer_frameParam_t pf1, pf2, pf3, pf4, pf5, pf6; // parallel formants in hz
speechPlayer_frameParam_t pb1, pb2, pb3, pb4, pb5, pb6; // parallel formant bandwidths in hz
speechPlayer_frameParam_t pa1, pa2, pa3, pa4, pa5, pa6; // amplitude of parallel formants between 0 and 1
speechPlayer_frameParam_t parallelBypass; // amount of signal which should bypass parallel resonators from 0 to 1
speechPlayer_frameParam_t preFormantGain; // amplitude from 0 to 1 of all vocal tract sound (voicing, frication) before entering formant resonators. Useful for stopping/starting speech
speechPlayer_frameParam_t outputGain; // amplitude from 0 to 1 of final output (master volume)
speechPlayer_frameParam_t endVoicePitch; // pitch of voice at the end of the frame length