**The science of sound waves**: Audio recorders capture sound waves, which are a type of mechanical wave that travels through the air as a pressure wave, causing our eardrums to vibrate.
**Frequency response**: Most audio recorders can capture frequencies between 20 Hz to 20,000 Hz, which is the range of human hearing.
**Bit depth and sample rate**: A higher bit depth (e.g., 24-bit) and sample rate (e.g., 48 kHz) result in higher quality recordings with less noise and distortion.
**Compressor microphones**: Some audio recorders use compressor microphones, which automatically adjust gain levels to reduce loud sounds and amplify quiet ones.
**Noise reduction techniques**: Many recorders use noise reduction techniques like noise gating, ducking, or spectral repair to minimize unwanted background noise.
**Crosstalk and phasing**: Audio recorders can suffer from crosstalk (electrical interference) and phasing (delayed sound wave interactions), affecting sound quality.
**Digital signal processing (DSP)**: Many modern recorders use DSP to apply effects like echo, reverb, or compression in real-time.
**Analog-to-digital converters**: Audio recorders use analog-to-digital converters to convert analog sound waves into digital signals that can be stored and edited.
**Latency and buffer size**: Audio recorders can experience latency (delay) and buffer size limitations, affecting real-time recording and playback.
**File formats and compression**: Recordings are often saved as compressed files (e.g., MP3, AAC) to reduce storage size, but uncompressed formats (e.g., WAV, AIFF) preserve higher quality.
**Polar patterns and microphone types**: Recordings can be influenced by microphone polar patterns (e.g., omnidirectional, cardioid) and types (e.g., condenser, dynamic).
**Acoustic impedance and room dynamics**: The acoustic properties of the recording environment (e.g., room size, surface materials) can significantly impact sound quality.