CER CER Audio Technology & Sound Quality Management 1 — Questions and Answers
Question 1: What is the recommended minimum sample rate for courtroom audio recordings to ensure acceptable speech intelligibility?
- 8,000 Hz
- 22,050 Hz
- 44,100 Hz (Correct answer)
- 96,000 Hz
Correct answer: 44,100 Hz
44,100 Hz (44.1 kHz) is the standard minimum sample rate for court recordings because it captures the full range of human speech and is widely compatible with playback and transcription systems.
Question 2: Which microphone polar pattern is MOST effective for minimizing ambient courtroom noise while recording a single witness?
- Omnidirectional
- Cardioid
- Figure-8 (bidirectional)
- Hypercardioid (Correct answer)
Correct answer: Hypercardioid
A hypercardioid pattern provides a narrower pickup angle than a standard cardioid, making it the most effective choice for isolating a single speaker while rejecting off-axis courtroom noise.
Question 3: What does 'clipping' refer to in audio recording, and why is it critical to avoid during court proceedings?
- Cutting out background noise with software filters
- Distortion caused by an audio signal exceeding the recorder's maximum input level (Correct answer)
- The physical trimming of audio files during editing
- Reducing the bit depth of a recording to save storage space
Correct answer: Distortion caused by an audio signal exceeding the recorder's maximum input level
Clipping occurs when an input signal is too loud and exceeds the recorder's ceiling, producing harsh distortion that makes speech unintelligible and can render a court recording legally unusable.
Question 4: A court electronic reporter notices a consistent 60 Hz hum on the recording. What is the MOST likely cause?
- A failing microphone capsule
- Electrical interference from nearby AC power lines or equipment (Correct answer)
- Excessive room reverberation
- A misconfigured sample rate on the digital recorder
Correct answer: Electrical interference from nearby AC power lines or equipment
A 60 Hz hum is the characteristic frequency of AC electrical interference in the United States and is almost always caused by ground loops or proximity to power cables and electrical equipment.
Question 5: What is the purpose of using a low-cut (high-pass) filter on courtroom microphones?
- To boost the clarity of high-frequency consonants in speech
- To eliminate low-frequency rumble, HVAC noise, and handling vibrations that muddy speech recordings (Correct answer)
- To increase the gain of the microphone signal before it reaches the recorder
- To convert analog audio signals to digital format
Correct answer: To eliminate low-frequency rumble, HVAC noise, and handling vibrations that muddy speech recordings
A low-cut filter removes unwanted low-frequency noise such as air conditioning rumble, footsteps, and microphone handling sounds that sit below the range of intelligible speech.
Question 6: Which file format is generally PREFERRED for archiving official court audio recordings due to its lossless compression?
- MP3
- AAC
- FLAC (Correct answer)
- OGG Vorbis
Correct answer: FLAC
FLAC (Free Lossless Audio Codec) preserves 100% of the original audio data without quality loss, making it the preferred archival format for official legal recordings that may be reviewed years later.
CER CER Audio Technology & Sound Quality Management 1
What is the recommended minimum sample rate for courtroom audio recordings to ensure acceptable speech intelligibility?