Audiobook Production Audio Editing and Post-Production 1 — Questions and Answers
Question 1: What is the ACX requirement for peak audio levels in a finished audiobook?
- -3 dB or lower (Correct answer)
- -6 dB or lower
- 0 dB
- +3 dB
Correct answer: -3 dB or lower
ACX requires that peak levels in the finished audiobook do not exceed -3 dBFS to prevent digital clipping during playback on various devices.
Question 2: What is the ACX requirement for average RMS (loudness) in a delivered audiobook?
- -10 to -14 dB RMS
- -18 to -23 dB RMS (Correct answer)
- -30 to -35 dB RMS
- -5 to -8 dB RMS
Correct answer: -18 to -23 dB RMS
ACX requires audiobook files to have an average RMS loudness between -18 dB and -23 dB RMS to ensure consistent playback volume across their platform.
Question 3: What does a 'noise gate' do during audiobook post-production?
- Boosts signal when voice is present
- Silences audio that falls below a set threshold (Correct answer)
- Removes plosive sounds from the recording
- Equalizes the frequency response of the track
Correct answer: Silences audio that falls below a set threshold
A noise gate automatically mutes the audio signal whenever its level falls below a defined threshold, removing room noise and breathing between words.
Question 4: What is 'de-essing' in audiobook audio post-production?
- Removing mouth click sounds
- Reducing harsh sibilant 's' and 'sh' sounds (Correct answer)
- Cutting low-frequency rumble from recordings
- Normalizing the overall loudness of the track
Correct answer: Reducing harsh sibilant 's' and 'sh' sounds
De-essing uses frequency-selective compression to tame harsh sibilant consonants like 's', 'sh', and 'ch' that can sound piercing on recordings.
Question 5: What is the standard room tone requirement at the beginning and end of each audiobook chapter per ACX guidelines?
- 0.5 seconds of silence
- 1 second of room tone
- 5 seconds of room tone (Correct answer)
- No room tone is required
Correct answer: 5 seconds of room tone
ACX requires at least 0.5 seconds of room tone at the head and tail of each file, though most narrators record 1–5 seconds for easier editing.
Question 6: Which type of equalizer cut is commonly applied to audiobook narration to remove low-frequency rumble?
- High-pass filter below 80–100 Hz (Correct answer)
- Low-pass filter above 10 kHz
- Bell cut at 1 kHz
- Shelf boost above 8 kHz
Correct answer: High-pass filter below 80–100 Hz
A high-pass filter rolls off frequencies below 80–100 Hz to remove HVAC rumble, floor vibrations, and other low-frequency interference from narration tracks.
Audiobook Production Audio Editing and Post-Production 1
What is the ACX requirement for peak audio levels in a finished audiobook?