Video Editing Audio Post-Production Syllabus

Audio Post-Production syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for Audio Post-Production in Video Editing, not a summary of it.

1. 1

   Audio Fundamentals

   2 topics

   • Sound Properties
   • Audio Levels and Metering
2. 2

   Dialogue Editing

   3 topics

   • Cleaning Dialogue
   • ADR and Voiceover
   • Dialogue Balancing
3. 3

   Music and Sound Design

   3 topics

   • Selecting and Licensing Music
   • Editing Music to Picture
   • Sound Effects and Foley
4. 4

   Mixing and Mastering

   3 topics

   • Audio Mixing Basics
   • EQ, Compression, and Effects
   • Loudness Standards

Audio Post-Production flashcards for Video Editing

24 of 50 cards from the Audio Post-Production deck — real questions with worked answers.

1. What is sound, physically speaking?

   Sound is a pressure wave: vibrations traveling through a medium (usually air) as alternating compressions and rarefactions that the ear perceives as sound.

2. What are the four fundamental properties of a sound wave a video editor must know?

   Frequency (pitch), amplitude (loudness), wavelength, and phase. Timbre (harmonic content/waveform shape) is often added as a fifth perceptual property.

3. What is the range of human hearing in frequency terms?

   Approximately $20\ \text{Hz}$ to $20{,}000\ \text{Hz}$ ($20\ \text{kHz}$), with sensitivity peaking around $2\text{–}5\ \text{kHz}$ and high-frequency hearing declining with age.

4. State the relationship between frequency, wavelength, and the speed of sound.

   $$v = f \lambda$$ where $v \approx 343\ \text{m/s}$ in air at $20^{\circ}\text{C}$, $f$ is frequency in Hz, and $\lambda$ is wavelength in meters.

5. What is the decibel (dB) and why is a logarithmic scale used for audio levels?

   The decibel is a logarithmic unit of ratio: for power, $L = 10 \log_{10}\frac{P_1}{P_0}$ dB; for amplitude/voltage, $L = 20 \log_{10}\frac{A_1}{A_0}$ dB. It is used because human loudness perception is roughly logarithmic and spans an enormous dynamic range.

6. How many decibels of change correspond to a doubling of sound pressure amplitude, and to a perceived doubling of loudness?

   Doubling amplitude adds $20 \log_{10} 2 \approx 6\ \text{dB}$; a perceived doubling of loudness requires roughly $+10\ \text{dB}$.

7. What does dBFS stand for and what is its reference point?

   Decibels relative to Full Scale — the digital metering scale where $0\ \text{dBFS}$ is the maximum possible digital level; all usable levels are negative (e.g., $-12\ \text{dBFS}$). Exceeding $0\ \text{dBFS}$ causes hard clipping.

8. What is the difference between a peak meter and a VU meter?

   A peak meter shows instantaneous maximum sample levels (to catch clipping); a VU meter shows a slower average level ($\approx 300$ ms integration) that better reflects perceived loudness. Peaks matter for distortion, VU/average for loudness balance.

9. What are typical dialogue level targets in dBFS when editing for video?

   Dialogue is commonly mixed to average around $-12$ to $-6\ \text{dBFS}$ on peaks (broadcast practice often averages near $-12\ \text{dBFS}$), leaving headroom so peaks never reach $0\ \text{dBFS}$.

10. What is headroom in audio mixing?

    The safety margin between the average operating level and the clipping point ($0\ \text{dBFS}$ digitally). It absorbs unexpected peaks and prevents distortion.

11. What is clipping and how does it sound?

    Clipping occurs when a signal exceeds the maximum level the system can represent; the waveform tops are squared off, producing harsh, crackly digital distortion that generally cannot be repaired — it must be avoided at recording and mixing.

12. What is signal-to-noise ratio (SNR)?

    The level difference in dB between the desired signal and the background noise floor: $\text{SNR} = 20 \log_{10}\frac{A_{signal}}{A_{noise}}$ dB. Higher SNR means cleaner audio.

13. What is room tone and why must an editor record it?

    Room tone is the ambient 'silence' of a location (30–60 seconds recorded on set). It is used to fill gaps between dialogue edits so cuts don't drop to dead silence and to smooth transitions between takes.

14. Name the three most common noise problems removed when cleaning dialogue.

    Broadband hiss (electronic/air noise), hum/buzz (mains interference at $50$ or $60\ \text{Hz}$ and its harmonics), and intermittent noises like clicks, pops, plosives, and mouth noise.

15. At what frequencies does electrical hum occur and what tool removes it?

    At the mains frequency — $60\ \text{Hz}$ (Americas) or $50\ \text{Hz}$ (Europe/Asia) — plus harmonics ($120/180\ \text{Hz}$, etc.). A notch filter or dedicated de-hum tool removes the fundamental and its harmonics.

16. How does spectral noise reduction (noise print method) work?

    The software 'learns' a noise profile from a signal-free section (the noise print), then subtracts that spectral fingerprint from the whole clip. Over-processing causes watery, robotic 'artifacting.'

17. What is a high-pass (low-cut) filter and why is it routinely used on dialogue?

    A filter that attenuates frequencies below a cutoff (commonly $80\text{–}100\ \text{Hz}$ for voice), removing rumble, wind, handling noise, and plosive energy without affecting speech intelligibility.

18. What is a de-esser and when is it applied?

    A frequency-selective compressor that reduces harsh sibilance ('s', 'sh' sounds), typically in the $5\text{–}10\ \text{kHz}$ range, applied to dialogue and voiceover that sounds spitty or piercing.

19. What does ADR stand for and what is it?

    Automated (or Additional) Dialogue Replacement — re-recording dialogue in a studio after the shoot, with the actor performing in sync to picture playback, to replace unusable production audio or change a line.

20. Why is ADR needed even on well-recorded productions?

    Location audio may be ruined by traffic, wind, or overlapping noise; performances may need altered lines, censorship replacements, or foreign-language dubbing; and wide shots often prevent close mic placement.

21. What is the difference between voiceover (VO) and narration recorded for ADR?

    VO/narration is non-sync speech from an unseen speaker recorded dry in a studio and laid over picture; ADR must lip-sync exactly to an on-screen performance. Both are studio-recorded, but only ADR requires sync matching.

22. What key steps make replaced ADR lines blend with production dialogue?

    Match the microphone and distance used on set, match performance energy, then match EQ and add reverb/ambience (worldizing) so the studio recording sits in the same acoustic space as the location sound.

23. What is a 'dialogue split' or checkerboarding in dialogue editing?

    Alternating dialogue clips across two or more tracks (A/B pattern) so each clip's head and tail can be cross-faded with room tone, enabling smooth, click-free transitions between takes and mics.

24. What does 'dialogue balancing' mean?

    Adjusting clip gain, fades, EQ, and compression shot-by-shot so every line of dialogue in a scene sounds consistent in level and tone, regardless of which mic, take, or camera angle it came from.

See more Audio Post-Production flashcards →

Planning Audio Post-Production for Video Editing

Audio Post-Production (Video Editing) FAQ