Understanding Plosives
Before diving in, it's important to understand what plosives *are*. They're the harsh "p," "b," "t," and "k" sounds that occur when a puff of air hits the microphone diaphragm, causing a sudden burst of low-frequency energy. This results in a distracting, often unpleasant, thump or pop in the recording.
Here are 6 methods for plosive removal in Adobe Audition:
1. Spectral Frequency Display Editing (Manual)
*This is often the most precise and effective, though it can be time-consuming.*
* How it Works: Audition's Spectral Frequency Display allows you to *see* the plosive as a visual anomaly. You can then isolate and reduce its amplitude.
* Steps:
1. Open your audio file in Audition.
2. Switch to Spectral Frequency Display: (Window > Spectral Frequency Display or click the waveform/spectral display toggle button at the top)
3. Zoom In: Use the zoom controls (usually located near the bottom of the screen) to zoom in tightly on the area where you hear the plosive. Look for a distinct, vertical burst of low-frequency energy. Plosives often appear as large, smeared blobs or vertical lines primarily in the low frequencies (below 200-300 Hz).
4. Selection Tool (Marquee): Select the Rectangle Selection Tool.
5. Select the Plosive: Carefully draw a rectangle around the visual representation of the plosive in the Spectral Frequency Display. Be precise; you only want to select the plosive itself, avoiding surrounding audio as much as possible.
6. Reduce Amplitude:
* Amplitude Panel: Go to Window > Amplitude.
* Click the "Gain" tab.
* Adjust the Gain: Reduce the gain (make it negative) to lower the amplitude of the selected area. Start with a small reduction (e.g., -3dB to -6dB) and listen back. Gradually reduce the gain further until the plosive is mitigated but the sound of the speaker's voice remains natural.
* Alternatively, use the Edit > Delete... command: Choose "Delete Time" and make sure "Re-join overlapping clips" is selected. This will effectively remove the audio and close the gap. This works best for very short, isolated plosives.
7. Repeat and Refine: Listen carefully after each adjustment. You might need to repeat the selection and gain reduction process multiple times to achieve the desired result. Sometimes you can use a combination of both the Gain adjustment and deleting a small amount of time.
8. Audition Pro Tip: Spectral Pan and Zoom (SPZ) tool is the first icon on the left in the waveform. If you hold down the left mouse button while in the SPZ tool, the selection area that you make is what the software will zoom in on. Using this, zooming in on a plosive in the waveform will be very quick and easy.
* Advantages: Highly precise control, avoids affecting other parts of the audio.
* Disadvantages: Can be time-consuming, requires a good understanding of the Spectral Frequency Display.
2. DeHummer Effect (Frequency Selective Reduction)
*This method can work well when plosives are concentrated in a specific frequency range.*
* How it Works: DeHummer is designed to remove hum, but it can be adapted to target the low-frequency rumble of plosives.
* Steps:
1. Open your audio file in Audition.
2. Apply the DeHummer Effect: Effects > Noise Reduction/Restoration > DeHummer.
3. Adjust the Settings: This is the crucial part. Experiment with the following:
* Frequency: Set the frequency to the area where the plosive is most prominent (usually between 50-150 Hz, but it can vary). Use a spectrum analyzer or your ears to pinpoint the primary plosive frequency.
* Gain: Start with a small negative gain reduction (e.g., -3dB). Increase it gradually until the plosives are reduced, but be careful not to make the audio sound thin or unnatural.
* Width: Adjust the width to narrow down the frequency range being affected. A narrower width is generally better to avoid impacting other parts of the audio.
* Order: Order usually refers to the complexity of the filter being used. Try different settings until you get the sound you are aiming for.
* Listen Carefully: Continuously listen to the audio while adjusting the settings to find the sweet spot where plosives are reduced without damaging the desired sound.
4. Consider applying the effect multiple times with subtle adjustments rather than one large reduction.
* Advantages: Relatively quick, can target a specific frequency range.
* Disadvantages: May affect other low-frequency content in the audio if not carefully adjusted.
3. Parametric Equalizer (Targeted Frequency Cut)
*Similar to DeHummer, but offers more precise control over frequency and bandwidth.*
* How it Works: Use a parametric EQ to create a narrow notch filter around the frequency of the plosive.
* Steps:
1. Open your audio file in Audition.
2. Apply the Parametric Equalizer Effect: Effects > Filter and EQ > Parametric Equalizer.
3. Create a Notch:
* Add a Band: Most parametric EQs have multiple bands. Use one band to create the notch.
* Set the Frequency: Again, identify the dominant frequency of the plosive (usually 50-150 Hz). Set the band's center frequency to this value.
* Set the Gain: Reduce the gain for that band (make it negative) to cut the frequency. Start with -3dB to -6dB.
* Adjust the Q/Width: Adjust the Q factor (or bandwidth) to create a narrow notch. A higher Q value means a narrower notch, targeting a more specific frequency. Experiment to find the narrowest notch that effectively reduces the plosive without affecting the surrounding audio.
4. Refine and Repeat: Listen carefully and adjust the frequency, gain, and Q until the plosive is reduced effectively and the audio sounds natural.
5. If necessary add a second notch filter in a higher frequency range to catch some of the harmonics of the plosive. This will require careful listening.
* Advantages: More precise control over frequency and bandwidth than DeHummer.
* Disadvantages: Requires a good understanding of EQ and frequency ranges. Can affect other low-frequency content if not carefully adjusted.
4. Graphic Equalizer (General Frequency Reduction)
*A simpler approach that can be useful for subtle plosives.*
* How it Works: The graphic equalizer allows you to reduce the overall level of several frequency bands, making it an easy way to try cutting some of the low end where plosives reside.
* Steps:
1. Open your audio file in Audition.
2. Apply the Graphic Equalizer Effect: Effects > Filter and EQ > Graphic Equalizer (either 10-band, 20-band, or 30-band).
3. Reduce Low Frequencies: Reduce the gain of the lowest frequency bands (typically the bands below 100 Hz or 200 Hz). Start with small reductions and listen carefully.
4. Refine: Adjust the band levels until the plosives are reduced, but be careful not to make the audio sound thin or muffled.
* Advantages: Very easy to use.
* Disadvantages: Less precise than Parametric EQ or Spectral Frequency Display editing. Affects a broader range of frequencies.
5. Volume Envelope (Manual Level Adjustment)
*This method works best for isolated plosives that don't overlap with important audio.*
* How it Works: Use the volume envelope to manually reduce the amplitude of the plosive.
* Steps:
1. Open your audio file in Audition.
2. Show Clip Volume: Right-click on the waveform and select "Show Clip Volume." This displays a yellow line across the waveform representing the volume envelope.
3. Add Control Points: Click on the yellow volume envelope line just before and just after the plosive to add control points.
4. Reduce Amplitude: Click and drag the control point in the middle of the plosive *downwards* to reduce the volume of that section. Smooth the transitions between the control points to avoid abrupt changes in volume.
5. Refine: Listen carefully and adjust the control points until the plosive is reduced without creating unnatural dips or bumps in the volume.
* Advantages: Precise control over the volume envelope.
* Disadvantages: Can be time-consuming. Works best for isolated plosives.
6. Dynamics Processing (Compression/Expansion - Use Sparingly)
*This is a more advanced method and should be used with caution, as it can easily negatively impact the overall audio quality.*
* How it Works: A compressor can reduce the overall dynamic range of the audio, thereby bringing down the loud plosives. An expander, conversely, can be used (with careful settings) to reduce the volume of signals *below* a certain threshold. This can help target the low-level rumble after the initial burst of the plosive.
* Steps:
1. Open your audio file in Audition.
2. Apply Dynamics Processing: Effects > Amplitude and Compression > Dynamics.
3. Compressor (Use Lightly):
* Set a Low Ratio: Start with a ratio of 2:1 or 3:1.
* Set a Threshold: Adjust the threshold so that only the loudest peaks (the plosives) are being compressed.
* Adjust Attack and Release: A fast attack will quickly reduce the plosives, but can sound unnatural. Experiment with attack and release times to find the best balance.
4. Expander (Use with Extreme Care):
* Set a Low Ratio: Start with a ratio of 2:1 or 3:1.
* Set a Threshold: Set the threshold so that only the quieter rumbles after the plosive are being expanded downwards (made quieter). This is tricky, as you don't want to affect quiet parts of the voice.
* Adjust Attack and Release: Similar to the compressor, adjust these to sound natural.
5. Refine: Listen carefully and adjust the settings until the plosives are reduced without noticeably affecting the overall dynamics of the audio.
* Advantages: Can be relatively quick.
* Disadvantages: Can easily damage the overall audio quality if not used carefully. Requires a good understanding of compression and expansion.
General Tips and Best Practices:
* Prevention is Key: Using a pop filter or positioning the microphone correctly (slightly off-axis) during recording is the *best* way to avoid plosives in the first place.
* Listen Carefully: Always listen to the audio critically after each adjustment to make sure you're not introducing new problems or negatively impacting the desired sound.
* Subtlety is Important: Often, a combination of subtle adjustments using different methods will yield the best results. Avoid heavy-handed processing.
* "Undo" is Your Friend: Don't be afraid to experiment and undo changes if they don't work.
* Practice Makes Perfect: The more you work with these tools, the better you'll become at identifying and removing plosives effectively.
* Save a Backup: Always save a backup copy of your original audio file before making any changes.
* Consider Batch Processing if you have a large number of audio files with consistent plosives. Audition allows you to save effect presets and apply them to multiple files.
By understanding these methods and practicing your technique, you'll be able to effectively remove plosives from your audio recordings in Adobe Audition. Good luck!