Perform audio editing processes (normalizing, trimming, compression)

11 Video and Audio Editing

Audio Editing Processes

In this unit we’ll learn how to make your audio sound great by normalising, trimming and compressing. Think of audio editing like preparing a playlist for a party: you want every track to sound balanced, the right length, and smooth transitions. 🎧

1. Normalising

Normalising is like turning up the volume on a TV so that the loudest part reaches the maximum level without distortion. The software scales the entire waveform so that the peak amplitude equals a target value (usually 0 dB). This keeps the relative dynamics of the track intact while ensuring it’s loud enough for the mix.

• Open the audio clip in your editor.
• Choose Normalise from the menu.
• Set the target peak level (e.g., 0 dB).
• Apply – the software rescales all samples proportionally.

Math note: If the current peak is $P_{\text{current}}$ and the target is $P_{\text{target}}$, the scaling factor is $S = \frac{P_{\text{target}}}{P_{\text{current}}}$. Every sample $x$ becomes $x' = S \times x$.

2. Trimming

Trimming removes unwanted silence or noise at the start or end of a clip. Imagine cutting the extra seconds from a song that you don’t want in your mix. 🎬

1. Zoom in to the waveform.
2. Place the cursor at the exact point where you want to cut.
3. Use the Cut or Delete function.
4. Check the new start/end points to ensure no abrupt jumps.

Tip: Use the Silence Detection tool if your software has it – it automatically finds and removes silent gaps.

3. Compression

Compression is like using a microphone with a built‑in limiter: it reduces the difference between loud and soft parts so that everything stays within a comfortable listening range. This is essential for podcasts, voice‑overs, and any audio that needs to be heard clearly on different devices. 📉

Compression workflow:

1. Insert a compressor plugin on the track.
2. Set the Threshold so that the loudest peaks sit just above it.
3. Choose a Ratio that reduces peaks but keeps dynamics (e.g., 3:1).
4. Adjust Attack and Release to match the tempo.
5. Listen and tweak until the audio sounds smooth and consistent.

Remember: normalising sets the overall level, trimming cleans up the edges, and compression balances the dynamic range. Master these steps and your audio will sound polished and professional! 🚀