AccuraConstants

Default octave mappings for voice-type-based shruti (tonic) selection.

In Indian classical music, a singer's shruti is the tonic note they tune to — often expressed as a Western pitch class (e.g., "D#"). The absolute frequency of that tonic depends on which octave the singer is placed in, which in turn depends broadly on voice type (male vs female range).

These maps encode a typical starting octave for each pitch class by voice type, useful as a default when no explicit octave is provided:

• MALE voices: tonic typically sits in octave 2 or 3 (roughly 65–130 Hz for C2–C3, 130–260 Hz for C3–C4). The mapping places "C"–"F" in octave 3 and "F#"–"B" in octave 2 so the tonic frequency stays within a typical male range for all pitch classes.

• FEMALE voices: one octave higher. "C"–"F" in octave 4, "F#"–"B" in octave 3.

Example

// Given a male singer who picked "D#" as their tonic:
val octave = AccuraConstants.MALE_SHRUTI_MAPPING["D#"]   // 3
val tonicHz = MusicTheory.noteLabelToHz("D#$octave")     // → 155.56 Hz

Note: These mappings are currently not consumed anywhere inside the SDK; they're exposed as a convenience for consumers building voice-type onboarding flows. If you rely on them, be aware they may be moved, removed, or reshaped in a future release — see the 2.0.0 orphaned-API audit for the decision on long-term support.

See also