Lesson 5 of 8
Sound: The Half of Film People Forget
Record clean dialogue, control room noise, and use music and effects without drowning your actors.
Learn it
Audiences forgive rough pictures but switch off bad sound within seconds.
Get the microphone close to the mouth — distance is the enemy. A phone on a boom pole beats an expensive mic across the room.
Record 30 seconds of 'room tone' (silence in the location) so the editor can patch gaps invisibly.
Key terms
- Room Tone
- A recording of a location's natural silence, used to smooth edits.
- Shotgun Mic
- A highly directional microphone that picks up what it points at.
- Lavalier
- A tiny clip-on microphone worn on clothing.
- Clipping
- Distortion caused when the signal exceeds 0dB and cannot be repaired.
- Foley
- Everyday sound effects recorded and added in post-production.
Rescuing a Noisy Location
You must film dialogue in a school corridor at break time.
- 1Scout: Listen with headphones before filming — you hear far more than with bare ears.
- 2Reduce: Switch off the vending machine hum and shut classroom doors.
- 3Get close: Boom the mic just out of frame, about 30cm above the actor's head, pointed at the mouth.
- 4Set levels: Rehearse the loudest line and set peaks around -9dB.
- 5Room tone: Ask everyone to stay silent and record 30 seconds of the corridor's own sound.
Checking audio levels (pseudocode)
pythonpeaks_db = [-22, -14, -8, -3, 0, -11]
for i, peak in enumerate(peaks_db, start=1):
if peak >= 0:
print("Take", i, "CLIPPED - reshoot, cannot be fixed")
elif peak > -6:
print("Take", i, "hot - lower the gain a little")
elif peak < -20:
print("Take", i, "too quiet - raising it will add hiss")
else:
print("Take", i, "good level")The safe window for dialogue is roughly -12dB to -6dB, with headroom before 0dB.
Try it
Order the sound steps for a location shoot from first to last.
- 1Position the microphone as close to the actor as possible, out of frame
- 2Set the recording level so the loudest line peaks near -9dB
- 3Record the takes
- 4Record 30 seconds of room tone before packing up
- 5Listen to the location on headphones and remove noise sources
Challenge
Your interview footage has loud fridge hum, echoey walls and dialogue peaking at -30dB. Write a fix plan: what you would change on a reshoot, and what you could realistically repair in editing.
Pick whichever way suits you — every mode earns the same bonus XP.
Write at least 40 more characters to submit.
Mark your own work
Guided walkthrough — 0/5 clues revealed
- Clue 1 locked — reveal it only if you get stuck.
- Clue 2 locked — reveal it only if you get stuck.
- Clue 3 locked — reveal it only if you get stuck.
- Clue 4 locked — reveal it only if you get stuck.
- Clue 5 locked — reveal it only if you get stuck.
Each clue costs 3 XP (never below 15 XP). You'd earn 30 XP right now.
Extension: Design a 3-layer sound mix for a 30-second chase scene: list the dialogue, effects and music layers and their relative volumes.