Information for Educators

When a student creates a practice plan, they pick one of two modalities:

• Match a target voice. The student chooses a specific reference voice from the Atavoice catalog, and each attempt is scored on how closely it matches that voice.
• Practice for perception. The student picks a perceptual direction — more masculine, more feminine, or more androgynous — and each attempt is scored on where it lands on that axis. A reference voice is still chosen for playback but the reported value is not matched against the reference voice.

Practice is done in a web browser with microphone access. There is no app to install.

Each calendar day the student is given a single assignment of ten conversational items, three to twelve words each. Roughly half are items they have struggled with in past sessions and half are new to them.

For each item the student listens to a reference rendition, records their own attempt, and sees an immediate report. They get up to three attempts per item (the initial recording plus two retries), and the score sent to the dashboard is the best of the three.

Remaining retries may be skipped early when the latest attempt clears the modality’s fast-path threshold:

• Match a target voice. Skip when the overall accuracy score is at least 80 out of 100 (the bottom of the “Almost Matching” tier).
• Practice for perception. Skip when the perception score lands in the tier the student picked — ≥ 60 for a feminine target, ≤ 40 for a masculine target, or 40–59 for an androgynous target.

All scores are 0–100.

Pitch (scalar, median F0):

pitch = 100 − max(0, |1200·log₂(user / target)| − 50) / 2

Resonance (per-formant percent contour, then weighted mean):

resonance_fk = mean over phase i:
                 100 − max(0, |uᵢ − tᵢ| / |tᵢ| · 100 − 5) / 1

resonance    = 0.2·resonance_f1 + 0.4·resonance_f2 + 0.4·resonance_f3

Breathiness (composite over CPP / H1–H2 / H1–A3 means):

breathiness_cpp  = 100 − max(0, |user − target| − 2) / 0.2
breathiness_h1h2 = 100 − max(0, |user − target| − 2) / 0.2
breathiness_h1a3 = 100 − max(0, |user − target| − 3) / 0.3

breathiness      = 0.20·breathiness_cpp + 0.40·breathiness_h1h2 + 0.40·breathiness_h1a3

Prosody (composite over F0 contour, intensity contour, F0 std):

prosody_f0  = mean over phase i:
                100 − max(0, |1200·log₂(uᵢ / tᵢ)| − 50) / 2
prosody_int = mean over phase i:
                100 − max(0, |z(uᵢ) − z(tᵢ)| − 0.2) / 0.01
prosody_std = 100 − max(0, |user − target| / |target| · 100 − 20) / 1

prosody     = 0.40·prosody_f0 + 0.30·prosody_int + 0.30·prosody_std

Overall (weighted mean ceilinged by a weighted geometric mean):

weighted = 0.40·resonance + 0.30·pitch + 0.15·breathiness + 0.15·prosody
ceiling  = pitch^0.35 · resonance^0.65
overall  = min(weighted, ceiling)

Score is mapped against a 0-100 scale. 0-40: “Seems masculine”, 41-60: “Seems androgynous”, 61-100: “Seems feminine”

Logistic helper (auto-inverts when feminine < masculine):

σ(x; masculine, feminine) = 100 / (1 + exp( −6·(x − ½(masculine+feminine)) / (feminine − masculine) ))

Pitch femininity (plateau outside 100–200 Hz):

pitch_fem = 0                                   if F0 ≤ 100 Hz
            100                                 if F0 ≥ 200 Hz
            100 / (1 + exp(−0.1·(F0 − 155)))    otherwise

Resonance femininity (F1 excluded):

res_fem = 0.45·σ(F2; 1500, 1700) + 0.55·σ(F3; 2500, 2900)

Breathiness femininity (CPP norms inverted: lower CPP = more feminine):

breath_fem = 0.40·σ(H1−H2; 1, 6)
           + 0.40·σ(H1−A3; 20, 35)
           + 0.20·σ(CPP;   20, 14)

Combination + cap (prosody intentionally excluded):

weighted   = 0.40·pitch_fem + 0.50·res_fem + 0.10·breath_fem
ceiling    = pitch_fem^0.35 · res_fem^0.65
perception = min(weighted, ceiling)

The anchor norms are explicit approximations and will be refined as the population of recorded attempts grows.

Student recordings are not persisted. Only the resulting numerical scores are written back to the database.

The microphone is only read inside an active practice session, and only after the student explicitly clicks the record button on a given item. The browser’s standard microphone permission applies; the page does not request or hold any background audio access.