Audio Terminology Glossary: Every Term Explained

When shopping for headphones or reading reviews, you'll encounter numerous technical terms. Understanding this vocabulary helps you make informed decisions and better appreciate what you're hearing. This glossary covers the most common audio terminology, organised by category for easy reference.

Sound Quality Terms

Bass

The low-frequency range of sound, typically 20-250 Hz. This includes deep rumbles, kick drums, and bass guitar. "Bass-heavy" headphones emphasise these frequencies, while "bass-light" headphones de-emphasise them.

Mids (Midrange)

The middle frequency range, approximately 250-4000 Hz. This is where most vocals and instruments reside. A "recessed midrange" means these frequencies are quieter relative to bass and treble, which can make vocals sound distant.

Treble (Highs)

The high-frequency range, approximately 4000-20000 Hz. This includes cymbals, sibilance (the "s" sound in speech), and the "sparkle" of music. Excessive treble can sound harsh or fatiguing.

Frequency Response

The range of frequencies a headphone can reproduce, listed as a range (e.g., "20 Hz - 20 kHz"). This tells you what the headphones can technically produce, but not how well or accurately they produce it.

Sound Signature

The overall tonal character of headphones—how they balance bass, mids, and treble. Common signatures include:

• Neutral/Flat: Balanced, accurate reproduction
• V-shaped: Boosted bass and treble, recessed mids
• Warm: Emphasised bass, smooth treble
• Bright: Emphasised treble, less bass

Soundstage

The perceived three-dimensional space in which sound appears. A "wide soundstage" makes music feel like it's happening around you rather than inside your head. Open-back headphones typically have wider soundstage than closed-back.

Imaging

The ability to precisely locate individual instruments and sounds within the soundstage. Good imaging lets you pinpoint where each element is "positioned" in the mix.

Separation

How distinctly different instruments and sounds can be heard apart from each other. Poor separation makes music sound "muddy" or "congested."

Detail

The ability to reveal subtle nuances in music—tiny inflections in vocals, room reflections, subtle percussion. More detailed headphones reveal more information in the recording.

Technical Specifications

Driver

The component that produces sound by converting electrical signals into sound waves. Think of it as a small speaker. Driver size is measured in millimetres (mm)—typical sizes are 40-50mm for over-ear headphones.

Driver Types

• Dynamic: Most common type; uses a diaphragm and voice coil like a speaker
• Planar Magnetic: Uses a thin diaphragm with embedded conductors; often delivers superior detail
• Balanced Armature: Compact drivers common in IEMs; efficient but typically limited bass
• Electrostatic: Premium technology using electrically charged diaphragms; requires special amplification

Impedance

Measured in Ohms, this indicates electrical resistance. Higher impedance headphones require more power to drive:

• Low impedance (16-32 Ohms): Easy to drive from phones and laptops
• Medium impedance (32-100 Ohms): May benefit from dedicated amplification
• High impedance (100+ Ohms): Typically requires dedicated headphone amplifier

Sensitivity

Measured in dB/mW or dB/V, this indicates how loud headphones get for a given amount of power. Higher sensitivity means louder at the same power level. This works with impedance to determine if headphones can be driven properly by a given device.

Headphone Types

Over-Ear (Circumaural)

Headphones with ear cups that completely surround your ears. Generally offer best sound quality and comfort for extended wear.

On-Ear (Supra-aural)

Headphones that rest on top of your ears rather than around them. More portable than over-ear but may be less comfortable for long sessions.

In-Ear Monitors (IEMs)

Earphones that insert into the ear canal, creating a seal. Provide excellent isolation and portability. Also called "in-ear headphones" or "earphones."

True Wireless (TWS)

Earbuds with no wires at all—each earbud is completely independent. Store in a charging case. Also called "true wireless earbuds."

Open-Back

Headphones with ear cups that allow air and sound to pass through. Typically offer more natural soundstage but leak sound and don't isolate from ambient noise.

Closed-Back

Headphones with sealed ear cups that block sound in both directions. Provide better isolation and bass, but may have less natural soundstage.

Semi-Open

A hybrid design with partially vented ear cups, offering a middle ground between open and closed characteristics.

Wireless Technology Terms

Codec

Software that encodes and decodes audio for wireless transmission. Common codecs include SBC (basic), AAC (Apple), aptX (Qualcomm), and LDAC (Sony high-res). Better codecs preserve more audio quality.

Latency

The delay between a signal being sent and heard. Measured in milliseconds (ms). Low latency matters for gaming and video. Under 40ms is ideal; under 100ms is acceptable for most uses.

Multipoint

The ability to connect to multiple devices simultaneously and switch between them seamlessly. Useful for those using phone and computer together.

Bluetooth Version

The version of Bluetooth protocol used (e.g., 5.0, 5.2, 5.3). Higher versions generally offer better range, stability, and power efficiency, but codec support matters more for audio quality.

Noise Cancellation Terms

Active Noise Cancellation (ANC)

Electronic noise reduction using microphones to detect external sound and create inverse waves that cancel it out. Most effective against low-frequency, constant sounds.

Passive Noise Isolation

Physical sound blocking through materials and design—essentially, how well the headphones seal against your ears. Works across all frequencies.

Transparency Mode (Ambient Mode)

A feature that uses external microphones to pipe ambient sound through to you, allowing you to hear your surroundings without removing headphones.

Adaptive ANC

Noise cancellation that automatically adjusts strength based on environmental noise levels, optimising the balance between isolation and battery life.

Audio Quality Terms

Hi-Res Audio

Audio with higher resolution than CD quality (44.1 kHz/16-bit). Typically refers to 96 kHz/24-bit or higher. Requires compatible source files and equipment to benefit.

Lossless

Audio compression that preserves all original data (like FLAC or ALAC). Contrasts with "lossy" formats (like MP3 or AAC) that discard some data to reduce file size.

Bit Rate

The amount of data used per second of audio, measured in kbps (kilobits per second). Higher bit rates generally mean better quality. CD quality is approximately 1411 kbps.

Comfort and Fit Terms

Clamping Force

How tightly headphones grip your head. Too much causes discomfort; too little allows slippage. Usually loosens slightly over time.

Ear Pad (Cushion)

The padding that contacts your ears. Materials include leather, pleather, velour, and foam. Affects comfort, sound, and isolation.

Ear Tip

Silicone or foam pieces that create a seal in IEMs. Proper tip selection is crucial for comfort, fit, and sound quality.

Nozzle

The tube on IEMs that directs sound into the ear canal. Some nozzles include filters to modify sound characteristics.

Other Common Terms

Burn-In

The controversial claim that headphones need extended play time before reaching optimal sound. Scientific evidence for dramatic changes is limited, though mechanical components may settle slightly.

DAC (Digital-to-Analog Converter)

The component that converts digital audio files to analog signals your headphones can play. All digital audio devices have DACs; dedicated DACs can offer improved quality.

Amplifier (Amp)

A device that increases the power of an audio signal. High-impedance or low-sensitivity headphones may require dedicated amplification.

EQ (Equalizer)

A tool for adjusting the volume of specific frequency ranges, allowing you to customise sound to your preferences or compensate for headphone characteristics.