Licenses

The Speaker Test has no runtime dependencies and no audio files: every sound is synthesized in the browser. It uses two self-hosted fonts, both under the SIL Open Font License 1.1.

Inter Copyright 2016 The Inter Project Authors (github.com/rsms/inter). Used for all text.
SIL Open Font License 1.1 (Inter)
JetBrains Mono Copyright 2020 The JetBrains Mono Project Authors (github.com/JetBrains/JetBrainsMono). Used for frequencies, levels and code.
SIL Open Font License 1.1 (JetBrains Mono)