Improving signal acquisition

Larry Bartlett, in his fabuouls book "Black and White," compared selecting photographic equipment for advanced amateurs and professionals to "walking across a mine field of poor advice and vested interest." I think the same is absolutely true of choosing audio recording and processing equipment for the purposes of speech field research. We simply cannot rely on off-the-shelf solutions. Instead, we must develop customized strategies (including equipment, technique, and methodologies) that will enable us to produce consistently good work. Signal acquisition is the foundation of successful field research. In a series of posts, I try to describe a few of the essential principles of field recording that are geared towards improving accuracy, consistency, reliability, and generalizability of speech data. I try to emphasize the importance of recording technique and understanding basic engineering and acoustic principles over equipment choices per se.

If you have any questions or suggestions for this and other articles, please send me an email and I will be happy to address them. Thanks!

Table of contents

Field Recording

• Speech acoustics and field recording
  • Definition of speech
  • Frequency response
  • Dynamic range
• Levels and metering
  • Three simple concepts
  • VU, PPM, and dBFS meters
  • Tone calibration
  • Practical benefits of tone calibration
• Microphone placement
  • General comments
  • Headset, lavalier, handheld, table top, and goose neck microphones
  • Spectral detail
  • Improving signal acquisition through testing
• Dealing with unwanted noise
  • What is noise?
• What are acceptable noise levels?
• Active noise reduction
• Microphone placement as a noise reduction technique
• Low-frequency noise
• Using a low-cut filter to reduce low-frequency noise
• Recording audio and video simultaneously
  • A/V signal routing
  • A/V synchronization
  • What do buy?
  • What about wireless audio?
• Multi-track recording
  • What is multi-track recording?
  • Why use multi-track recording?
  • Scenario #1: Expensive but good
  • I am exaggerating a bit
  • Scenario #2: The hack
  • More people, more trouble
  • A possible alternative

Recommendations

• Field recording starter kit
• Mix and match: How to match different pieces of recording technology
• DIY headset: How to convert a lavalier microphone to a headset

Reviews

• Referer to this page for current reviews

Audio technology

• Microphones
  • Dynamic microphones
  • Condenser microphones
  • Proximity effect
  • Polar patterns
  • Polar patterns and proximity effect
  • Recommendations
• Recorders
  • Analog recorders
  • MiniDisc recorders
  • DAT recorders
  • Solid state recorders
  • Hard disk recorders
• A/D conversion
  • A/D conversion fundamentals
  • A/D workflow
  • Improving A/D conversion
• SMIL with Akustyk
  • What is SMIL?
  • Why create SMIL presentations?
  • What is the structure of SMIL?
  • Akustyk creates web pages