A Guide for Academic Content Creators

Introduction

Digital audio has revolutionized academic communication, making knowledge sharing more accessible than ever. This presentation covers the fundamentals of digital sound and provides practical guidance for creating quality academic podcasts (at a wide range of budgets and skills).

Since we only have a short time, we will cover only some basic concepts and a few possible digital tools and set-ups. Realizing the limitations of our time with you, we have provided you with a number of helpful links and resources.

Audio Resources & References — A list of key organizations, standards, tech, courses, and more to help you get started with audio.
Podcasting Resources and Podcasting Bibliography provide an in-depth focus on the world of academic podcasting. But don’t forget to check out Academic Podcasts about Africa.
Oral History Resources, Technology, & Standards is a very helpful list of resources developed by oral historians. While oral history interviewing overlaps and yet differs from podcasting, the resources by oral historians (particularly the best practices and tech advice and release forms) can be immensely helpful for podcasters.
Finally, we are developing a short guidelines list of helpful tips that we use in our classrooms, Top 10 Techniques of Successful Scholarly Podcasters. It is in the early stages and we value your feedback and additions.

Part 1: Understanding Digital Audio

What is Digital Audio?

Digital audio is the representation of sound in binary form through a process called Pulse Code Modulation (PCM). This process involves:

Sampling: Converting continuous analog waves into discrete digital values
Quantization: Assigning binary values to these samples
Encoding: Storing these values in a specific format

Let’s make this simpler, imagine analog sound as a wave:

It is always nice to see sound as a simple wave but in rea life it is a lot messier.

Yet imagine now you want to turn this mess of waves into a pile of bytes & bits that a computer can handle. In a simplified way, we would need to sample of the wave at a series of regular and discrete moments (sampling). At every sample point we would need to capture a quantity of the sound (quantization). And finally, we would need to turn it into a code that the computer can understand (encoding).

Key Concepts in Detail

Sample Rate Explained
- 44.1kHz: 44,100 samples per second (CD standard)
- 48kHz: Professional broadcast standard
- 96kHz: High-resolution audio
Nyquist Theorem: Sample rate must be twice the highest frequency you want to capture
- Human hearing range: 20Hz – 20kHz
Bit Depth Technical Details
- 16-bit: 65,536 possible values per sample
- 24-bit: 16,777,216 possible values per sample
- 32-bit (float): 4,294,967,296 (a big poop load)
Dynamic Range:
- 16-bit = ~96dB
- 24-bit = ~144dB
- 32-bit = ~1528dB
Audio Formats Deep Dive
- WAV/AIFF
  - PCM encoding
  - ~10MB per minute (stereo, 44.1kHz/16-bit)
  - Ideal for editing and archiving
- MP3 Technical Specs
  - Psychoacoustic modeling
  - Variable Bit Rate (VBR) vs Constant Bit Rate (CBR)
  - Joint stereo encoding
  - Recommended settings: 192-320kbps for final distribution
- AAC Advantages
  - Better algorithm than MP3
  - Superior at lower bitrates
  - Native support on iOS/Android

Part 2: Essential Equipment

At the heart of the matter, the most important thing to good podcasting is good sound, and when it comes to good sound, there are three keys (among many):

Selection of sound-controlled space (or studio).
Selection of microphone and its placement.
Selection of podcasting setup.

Selection of sound-controlled space (or studio):

Professional studio is always first choice, but we rarely have access to such luxury.
Close your eyes and imagine the sound you want for your space.
Record in treated/dampened space to minimize reflections
Stay away from walls/hard surfaces
Use acoustic panels/blankets if needed

Selection of microphone and its placement:

Individual mics preferred over shared
Position speakers facing each other
Maintain equal distance from mics (6-8 inches from mouth, slightly off-axis — pointing toward corner of mouth) to reduce plosives
Use a pop filter to further minimize breath/plosive sounds
Set gain so peaks hit around -12 to -6 dB
Test levels before recording
Avoid touching mic/stand during recording
Monitor audio with headphones
Consider using mic arm/stand for stability
Practice proper mic technique before important recordings
Microphones by the numbers
- Sound to Noise Ratio
- Frequency response
Some we use —
- Dynamic Microphones (moving coil technology)
  - Shure SM58: -54.5dBV/Pa sensitivity
- ATR2100x-USB: Dual XLR/USB outputs, 24-bit/192kHz capable
- Condenser Microphones (capacitor-based technology, requires 48V phantom power)
- Rode NT-USB: -36dB sensitivity, 16-bit/48kHz
USB Mics
- Blue Yeti: Multiple polar patterns, 16-bit/48kHz
- Synco Lavaliers:

When buying a mic for podcasting, focus on these key specifications:

Type: Choose between dynamic (durable, good for noisy spaces) or condenser (sensitive, ideal for treated studios) microphones [3][4].
Polar Pattern: Cardioid is common for podcasts as it isolates the speaker’s voice while reducing background noise [4][5].
Frequency Response: Look for a range that captures clear lows and highs, typically 20 Hz to 20 kHz [1][3].
Connectivity: USB mics are plug-and-play; XLR mics offer better quality but require an audio interface.

Signal-to-Noise Ratio (SNR)
The signal-to-noise ratio is a critical specification that directly impacts the quality of your recordings:
Definition: SNR represents the difference between the microphone’s output signal level and its noise level4.

Measurement: It’s typically measured using a 1 kHz sine wave at 94 dB SPL (1 Pa)4.
Ideal Range:
60 dB or greater is considered good
70 dB is better
80 dB or higher is ideal6
Why SNR Matters:
Higher SNR means cleaner recordings with less background noise.
It affects the microphone’s ability to capture faint, distant sounds.
A higher SNR can increase the detection range for audio, especially important for capturing a wide sound space.

When selecting a microphone, aim for the highest SNR possible within your budget. This will ensure your podcast recordings have clear audio with minimal background noise, making it easier for your audience to engage with your content.

Mic Citations:
[1] https://thepodcastconsultant.com/blog/podcast-microphones
[2] https://www.musicradar.com/news/best-podcasting-microphones
[3] https://www.bestbuy.com/discover-learn/how-to-select-the-best-podcasting-microphone/pcmcat1647525556614
[4] https://riverside.fm/blog/podcast-microphone
[5] https://www.shure.com/en-US/insights/choosing-a-microphone-for-podcasting
[6] https://www.descript.com/blog/article/how-to-choose-a-mic-for-your-podcast
[7] https://www.thepodcasthost.com/equipment/the-best-podcasting-microphones-on-the-market/
[8] https://www.bhphotovideo.com/explora/pro-audio/buying-guide/how-to-choose-a-microphone-for-podcasting

Selection of podcasting setup.

Computer or Smart Phone and 2 USB Mics: In the old days (a decade or so ago) we would frown upon using an iPhone or your Laptop for recording interviews, but the USB Mics and ability to capture good sound has greatly increased. A good USB mic as those noted above connected directly to your Smart Phone. We will demonstrate a couple of set ups. The one caveat is that your laptop will not recognize 2 mics but this problem can be easily solved (and for free).
- Apple: https://youtu.be/jw5dID426lI
- Windows: https://www.supportyourtech.com/articles/how-to-use-two-microphones-at-the-same-time-on-windows-11-a-guide/
Digital Recorder and 2 Mics: recorders can make for a great sound setup that include things like recording a person joining the podcast on their smartphone. We will demonstrate some examples.
- Zoom P4 and Bluetooth Adapter
- Zoom F3 (32 bit float) makes for easy recording and less concern about levels.
Podcast set-up with mixing board and preset mic placement

Yeti USB Microphone

Audio Interface Specifications

Preamp quality: EIN (Equivalent Input Noise)
A/D conversion specifications
Latency considerations
Focusrite Scarlett Solo:
- 24-bit/192kHz capability
- 111dB dynamic range
- -128dBu EIN
PreSonus AudioBox:
- 24-bit/96kHz capability
- MIDI I/O included
- Class A preamps

Recorders

There are a wide range of digital sound recorders that can fit all budgets. One of our favorites for podcasting is the Zoom P4 with the Bluetooth adapter for smartphones. It is great recorder for the money allowing you to set up four participants (including one on the phone). One of our favorites for the field is the Zoom F3. A tough little unit (although a bit more expensive), it is very easy to use and with 32 Bit float allows one to forget about monitoring levels..

Software Technical Capabilities

Recording Software Comparison
- Audacity: 32-bit float processing
- GarageBand: 24-bit internal processing
- Adobe Audition: 32-bit float, spectral editing
Remote cRecording Platform Specs
- Zencastr: WAV recording, automatic backup
- Squadcast: Up to 4K video, 48kHz audio
- Riverside.fm: Local recording up to 48kHz/24-bit

Part 4: Academic Podcasting Guidelines

Content Structure Technical Standards

Episode duration optimization: 20-40 minutes
Speech rate: 150-160 words per minute
Signal processing chain:
- High-pass filter: 80Hz, 12dB/octave
- De-esser: 4-8kHz range
- Compression: 2:1 to 4:1 ratio
Metadata standards for academic citation

Accessibility Technical Requirements

Transcript formats: SRT, WebVTT
Audio description requirements
WCAG 2.1 compliance specifications
Speech-to-text accuracy metrics

Part 5: Post-Production

Advanced Editing Techniques

Good production makes for easier post-production
Adjust frequencies with equalization(EQ)
Utilize wavelengths as a visual editing tool
Simple fades (in and out) go a long way
Edit with headphones, but quality check with both headphones and external speakers

Part 6: Distribution Strategies

Platform Analysis

Podcast Hosting Services
- Libsyn: Unlimited bandwidth, detailed analytics
- Podbean: Educational pricing, automated distribution
- Anchor: Free hosting, Spotify integration
- Buzzsprout: Clean analytics, transcription services

Analytics and Impact Measurement

Download metrics interpretation
IAB certification standards
Geographic distribution
Device analytics
Academic Impact
Citation tracking
Altmetric scoring
Academic engagement metrics
Impact factor correlation

Digital African Studies

Digital Audio & Academic Podcasting