speak

Synthesize speech from a klattsch phoneme string. Returns base64 WAV audio.

What This Is

klattsch is a formant speech synthesizer (late-70s/early-80s style — think Votrax, SAM). You give it a string of ARPAbet phoneme codes with optional voice control directives, and it renders a WAV audio file.

How To Use This Tool

Step 1: Build a phoneme string

Write ARPAbet phonemes separated by spaces, with control directives mixed in. Use the text_to_phonemes tool first to convert English text, then refine by hand.

Step 2 (optional): Set voice character

Prefix your utterance with control directives to set the voice:

• bN: base pitch in Hz (b120 = default male, b200 = female, b280 = child)

• rN: per-phoneme duration in ms (r80 = fast, r110 = normal, r250+ = sung)

• sN: formant scale (1.0 = male, 1.17 = female, 1.3 = child)

• vN: vibrato depth in Hz (v3-v6 = expressive, v0 = off)

• hN: breathiness 0..1 (h0.3 = airy/whispery)

• gN: vocal effort 0=lax..1=tense (default 0.5)

• tN: spectral tilt -0.9=darker..+0.9=brighter (t-0.4 = warm, t0.3 = bright)

Step 3: Add prosody (intonation)

• ! after a vowel for stress: DH AE! T = "THAT" with emphasis

• +N/-N on vowels for pitch changes: AY+20 = rising "I", D AH N(-30) = falling "done"

• (+N)/(-N) for transient ornaments (don't carry forward)

• , ; . for pauses: 100ms, 200ms, 300ms

Step 4: Render

Pass the complete string to this tool.

Quick-Reference Voice Presets

Intonation Patterns That Sound Natural

Falling statement (period): last vowel gets -20 to -30 e.g. D AH N(-25) Rising question: last vowel gets +20 to +30 e.g. R EH D IY(+25) Listing items: each item rises, last falls e.g. AE(+15) P AH L Z(+15) AO R AH N JH(-20) Excited: higher base pitch, faster b140 r85 ... Serious/deep: lower base pitch, slower b95 r115 ... Sarcastic: exaggerated pitch swings AY+30 M . S OW(-30) . S AH R K AE S T IH K

Singing With Note Names

Instead of Hz for b, use note names: bC4, bD#4, bEb4, bF4, bG4, bA4, bB4 Middle C = C4 (261Hz), A4 = 440Hz Set r250-r400 per phoneme, group notes with parentheses: bC4 r300 ( HH AH ) ( L OW ) bE4 ( W ER L D )

Example Strings

1. "Hello world" (male): b120 r100 s1.0 HH AH L OW . W ER L D

2. "How are you?" (female, rising): b200 s1.17 HH AW . AA R . Y UW(+25)

3. "I am NOT impressed" (stress on NOT): b120 AY . AE M . N AO T! . IH M P R EH S T(-20)

4. "The quick brown fox" (energetic): b135 r90 t0.2 DH AH . K W IH K . B R AW N . F AA K S

5. Sing "Twinkle twinkle" (two notes): bC4 r300 ( T W IH NG ) ( K AH L ) bG4 r300 ( T W IH NG ) ( K AH L )

6. Dramatic movie trailer voice: b95 r140 s0.95 v4 t-0.3 g0.7 IH N . AH . W ER L D(-25) .

7. Robot announcement: b130 r85 s1.0 v0 h0 g0.8 t0.4 AH T EH N SH AH N . P L IY Z

8. Whispered secret: b110 r105 v0 h0.5 g0.1 s1.0 P S T . D OW N T . T EH L . EH N IY W AH N

Phoneme Categories (all 39 phonemes)

Vowels: IY IH EH AE AA AO AH UH UW ER AY AW EY OW OY Sonorants: W Y R L M N NG Fricatives: F TH S SH V DH Z ZH HH Stops: P B T D K G (these get automatic burst + silence) Affricates: CH JH

⚠️ P, B, T, D, K, G, CH, JH are stop consonants — they include an automatic silence-burst pattern. Don't add extra pauses after them.