Audio Processing Tools

These processing tools handle the most common audio preparation tasks. Here's what each one does and when to use it.

Dynamic range compression is one of the most important tools for spoken content. It reduces the volume difference between the loudest and quietest parts of a recording, making everything more consistent and easier to listen to. Podcasters use compression so the listener doesn't need to constantly adjust their volume. The compressor attenuates signals that exceed a threshold. A threshold of -18 dB with a 4:1 ratio is a good starting point for voice.

Equalization shapes the frequency content of your audio. The 3-band equalizer gives you control over bass (below 320 Hz), midrange (around 1000 Hz), and treble (above 3200 Hz). Boosting bass adds warmth, boosting mids brings clarity to speech, and boosting treble adds presence. Cutting frequencies is just as useful: reducing bass removes rumble, cutting mids tames boxy or nasal qualities, and reducing treble tames sibilance.

Pitch shifting changes the musical key of audio without altering its duration. Musicians use it to transpose a track to match their vocal range, and content creators use it for harmonies or special effects. Each semitone represents one piano key. Shifting up 12 semitones raises pitch by one full octave. The algorithm works well for moderate shifts but may introduce artifacts at extreme values.

Volume boosting and normalization serve different purposes. The volume booster multiplies the entire signal by a fixed amount, useful when a recording is uniformly too quiet. Normalization analyzes the peak level and applies the exact gain needed to reach maximum volume without clipping. Use normalization for consistent results across multiple files, and the booster when you need a specific amount of amplification.

Fade effects smooth out the start and end of any audio. A fade in gradually increases volume from silence, avoiding abrupt starts. Fade out gradually decreases to silence, creating a natural ending. Typical durations range from 0.5 to 3 seconds: shorter for transitions, longer for endings.

All processing uses the Web Audio API's OfflineAudioContext, which renders the entire file at once. This gives you consistent results regardless of your device's processing power. The output is always uncompressed WAV to preserve quality.