I have a couple hundred small voice clips used for teaching correct pronunciation of words. Some of the recordings are quieter than others and most have some silence (not true silence) at the beginning and end. I am looking for a way to quickly amplify and trim the files rather than doing them one by one.

I am currently trying to use Audacity but am open to other suggestions (preferably Mac first or Linux second as a second option).

I have been looking at using Audacity Chains to automate this, but it looks like it doesn't work with Amplify. It does work with Normalize, but I am not sure if this is what I want, because in my mind it will distort the audio (but please correct me if I am wrong) and thus the user would not hear the correct pronunciation of the words.

How can I go about automating the trimming and amplification of these sound clips?

  • Normalise will only ensure that the peak volume is at a specific level. It will not 'auto-level' so that all snippets sound to be the same perceptual loudness. For that you would need a compressor [probably a multi-band] &/or limiter. I don't know Audacity well enough to suggest a specific.
    – Tetsujin
    Commented Jun 26, 2019 at 18:26
  • Do you have access to MATLAB? It can easily read wave files and allows to make up a certain threshold which means speech; e.g. normalize the responses against the half-way point of the file where you are sure that there is speech and take like a second or so to make sure there is no silent gap between words/formants. Then say e.g., everything below 1% of that mean amplitude in a period in, e.g., the first 1 second (dependent on the duration of your files) and last 1 second of your files (i.e., the potential times that silence is recorded) should be deleted. It all depends on your files though!
    – AliceD
    Commented Nov 23, 2019 at 21:52

1 Answer 1


You can use protools 'strip silence' feature. This will allow you to set working thresholds in order to 'cut' audio regions/clips based on the audio level of the content. Strip Silence allows you to either remove the audio, or remove the silence.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.