Audio Volume Changer

What this tool does

Audio Volume Changer boosts or reduces the level of a recording in decibels and shows peak and RMS levels before and after. Normalise to a peak target, match an average loudness for speech or music, and use the soft limiter to stop loud parts from clipping.

A recording that is too quiet forces listeners to turn their speakers right up, and the next file they play blasts them. Phone voice memos, lecture recordings and old MP3s are often 10 dB or more below where they should be, while some downloads are so hot that they distort.

This tool decodes the file with the Web Audio API and multiplies every sample by a gain factor calculated from decibels (gain = 10^(dB/20)). You can type the change directly, or let the tool calculate it: peak normalisation raises the loudest sample to a target such as -1 dBFS, and loudness matching sets the RMS (average) level, which tracks perceived loudness better than the peak. A soft limiter rounds off any peaks that would exceed -1 dBFS instead of hard-clipping them. Everything runs locally.

How to use Audio Volume Changer

1. Drop an audio file onto the upload area.
2. Choose a Method: Change by dB, Normalise peak or Match loudness.
3. Set the Gain, Peak target or Average level (RMS) target, or click a preset such as Podcast (-16).
4. Keep Soft limiter switched on unless you need an exact linear gain.
5. Compare the Peak and Average (RMS) readings before and after, and use Play original and Play result to listen.
6. Choose the WAV bit depth and click Download WAV.

Tips for better results

• +6 dB roughly doubles the signal amplitude and -6 dB halves it; +10 dB is perceived as about twice as loud.
• Peak normalisation cannot make a file with one loud spike much louder; use Match loudness with the limiter instead.
• Around -16 to -20 dBFS RMS is comfortable for spoken word; modern pop music sits nearer -10 to -12.
• Leave about 1 dB of headroom below full scale so later MP3 or AAC encoding does not create clipping.

Common use cases

• Boosting a quiet voice memo or phone call recording so it is easy to hear.
• Evening out the levels of several podcast or course clips before publishing.
• Turning down a loud sound effect or notification sound.
• Preparing music tracks at a consistent level for a presentation or event.

Common mistakes to avoid

• Turning off the limiter and applying large gain: any sample pushed beyond full scale is cut flat, which sounds harsh. The tool warns you with a count of clipped samples.
• Boosting a noisy recording by 20 dB and expecting clarity; the background hiss is boosted by exactly the same amount.
• Assuming RMS matching equals broadcast loudness (LUFS); RMS is unweighted, so treat it as a close guide rather than a compliance measurement.