Audio Settings¶

Configure audio processing parameters.

Overview¶

Audio settings control how recordings are processed and augmented.

Sample Rate¶

Default: 16,000 Hz

The AST model is designed for 16kHz audio. All input is resampled.

# In config.py
SAMPLE_RATE = 16000

Do Not Change

Changing the sample rate is not recommended as it requires a different pre-trained model.

Duration¶

Default: 1.0 second (16,000 samples)

Audio clips are padded or trimmed to this duration.

Input Duration	Action
< 0.5s	Rejected as too short
0.5s - 1.0s	Zero-padded to 1.0s
1.0s - 2.0s	Trimmed or used as-is
> 2.0s	Trimmed to 1.0s

Mel Spectrogram¶

Parameters for mel spectrogram extraction:

Parameter	Value	Description
`n_mels`	128	Number of mel frequency bins
`n_fft`	400	FFT window size
`hop_length`	160	Samples between frames
`fmin`	0	Minimum frequency
`fmax`	8000	Maximum frequency

Recording Constraints¶

Web UI Settings¶

Parameter	Min	Max	Default
Recording duration	0.5s	3.0s	1.5s
Recordings required	1	5	3
Auto-stop on silence	0.5s	2.0s	0.8s

Audio Validation¶

Recordings are validated for:

Check	Requirement
Energy	Above silence threshold
Duration	Within allowed range
Clipping	No sustained clipping
Format	Web Audio compatible

Noise Settings¶

Background noise configuration:

Parameter	Default	Range
`noise_snr_min`	-20 dB	-30 to -10
`noise_snr_max`	-5 dB	-10 to 0

Lower SNR = more noise relative to signal.

Voice Activity Detection¶

Simple energy-based VAD:

Parameter	Default	Description
`vad_threshold`	0.02	RMS energy threshold
`vad_min_frames`	10	Minimum speech frames
`vad_frame_size`	400	Samples per frame

Configuration Example¶

# src/wakebuilder/config.py

AUDIO_CONFIG = {
    # Core settings
    "sample_rate": 16000,
    "duration": 1.0,

    # Mel spectrogram
    "n_mels": 128,
    "n_fft": 400,
    "hop_length": 160,
    "fmin": 0,
    "fmax": 8000,

    # Recording constraints
    "min_recording_duration": 0.5,
    "max_recording_duration": 3.0,

    # Validation
    "energy_threshold": 0.02,
    "clipping_threshold": 0.99,
}