This version adds many new features: - Higher cascade formants F7 (6500 Hz) and F8 (7500 Hz) for spectral presence above F6 (Rabiner 1968 defaults). Nyquist-proximity fade auto-mutes them at low sample rates. - Parallel F7/F8 resonators for fricative high-frequency presence (amp 0.15/0.07). - 2x source oversampling for cleaner harmonics at lower sample rates. - Dual-oscillator chorus for vocal fold asymmetry (VoicingTone V5): chorus depth and variation sliders for natural vocal fold jitter. - Brown noise aspiration blend: white/brown noise mix by sample rate (44k=100% white, 22k=70/30, 16k=50/50). Fixes aspiration thinness at lower sample rates. - Glottal sharpness rebalanced for F7/F8 spectral dynamics. - Transition bandwidth widening after obstruents: decaying BW boost across first 3 micro-frames, scaled by F2 sweep width. - Word-final stop audibility improved: stop floor 4ms to 6ms, word-final bonus 5ms to 8ms, voiced alveolar softening eased. - Voiced consonant bandwidths widened for smoother transitions. - Rhotic diphthong collapse: vowel+liquid tied pairs (/ER/ in "shared", "scared", "stairs") now collapse into micro-frame diphthongs with proper formant sweep. Previously rendered as two crushed tokens with no glide. - SQUARE diphthong pairScale 1.40 for the wide F3 sweep (2500 to 1620 Hz). - Diphthong rate compensation bumped 0.15 to 0.30; onset hold exponent 1.3 to 1.6 for better vowel identity at high rates. - Fixed diphthong tie bar blocking dialect replacements: eSpeak marks diphthongs with tie bars (e-tied-I) which blocked I-to-I_es substitution. Vowel-vowel tie bars are now stripped early; affricate tie bars preserved. (issue #82, reported by @gregodejesus2) - New `I_es` parallel formants tuned to Spanish-peripheral [i] target (Quilis 1981, Martinez Celdran): pf1 330, pf2 2150, pf3 2850. Previously carried English-lax values. - New `U_es` phoneme for Spanish [u] diphthong offglides (/au/, /eu/): F1=340, F2=780. Base /U/ was English-lax (F1=405, F2=900). - `autoDiphthongOffglideToSemivowel: false` for Spanish to preserve dialect-specific offglide phonemes. - Geminate /ss/ deduplication from eSpeak number expansion ("200" no longer "dosssientos"). - Fixed "behind a wall" quality at 22050 Hz: disabled oversampling decimation and anti-alias LP at 22050+ Hz. Sharpness raised 2.0 to 3.0. This was the most-reported audio quality issue since v3.0.