How do you tell one effect or process apart from another by ear, and what are the tell-tale signs of each?
Distinguishing effects and processing by ear: the audible signatures of reverb, delay, chorus, flanger, phaser, distortion, compression, EQ and pitch correction, telling similar effects apart, and recognising synthesis types and sampled material.
A focused answer to the Edexcel 9MT0 effect-identification content, covering the audible signatures of reverb, delay, chorus, flanger, phaser, distortion, compression, EQ and pitch correction, telling similar effects apart, and recognising synthesis and sampling.
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What this dot point is asking
Edexcel wants you to tell effects and processes apart by ear: the audible signatures of reverb, delay, chorus, flanger, phaser, distortion, compression, EQ and pitch correction, distinguishing similar effects, and recognising synthesis types and sampled material. This precise discrimination is exactly what Component 3 tests, where you must name the right effect, not just a vaguely similar one.
The answer
Time-based effects: reverb versus delay
Modulation effects: chorus, flanger, phaser
Dynamics and tone: distortion, compression, EQ
Pitch correction, synthesis and sampling
Examples in context
When you correctly separate a delay's countable echoes from a reverb's wash, or a flanger's jet sweep from a chorus's thickening, you are doing the precise discrimination Component 3 demands. When you recognise a buzzy filtered sawtooth as a subtractive synth or a chopped re-pitched phrase as a sample, you identify the source by ear. Knowing the audible signature of each effect and process is what lets you name the right one under exam conditions.
Try this
Q1. How do you tell reverb from delay by ear? [2 marks]
- Cue. Reverb is a smooth dense wash with no countable repeats; delay has distinct, countable echoes.
Q2. What is the audible difference between a flanger and a chorus? [2 marks]
- Cue. Flanger = strong jet-like sweep (very short delay); chorus = gentle detuned thickening (longer delay).
Q3. Name one audible sign that a sound is distorted. [1 mark]
- Cue. Added harmonics giving a gritty, edgy or fuzzy character.
Exam-style practice questions
Practice questions written in the style of Pearson Edexcel exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
Edexcel 9MT0/03 20204 marksExplain how you would tell the difference between a reverb and a delay by ear, and how you would tell a flanger from a chorus.Show worked answer →
Reverb and delay are both time-based, but they sound different. Reverb is a dense, continuous wash of overlapping reflections that decays smoothly; you cannot pick out individual repeats, and it gives a sense of a room or space. Delay produces distinct, discrete repeats (echoes) that you can count, often spaced rhythmically; you hear the signal repeat clearly rather than blur into a wash.
A flanger and a chorus are both LFO-modulated delayed copies of the signal, but the delay time differs. A flanger uses a very short modulated delay, producing a strong, sweeping, whooshing, jet-like comb-filter effect that is obvious and metallic. A chorus uses a longer modulated delay, producing a gentler thickening and widening that sounds like several slightly detuned voices, without the strong sweep of a flanger.
Markers reward reverb = dense smooth wash (no countable repeats) versus delay = distinct countable echoes, and flanger = very short delay (strong sweeping jet-like sweep) versus chorus = longer delay (gentle detuned thickening).
Edexcel 9MT0/03 20234 marksA bass sound in a recording is heavily processed. Describe the audible signs that would tell you it is (a) distorted and (b) compressed, and how you would recognise that a sound is synthesised rather than recorded.Show worked answer →
Distortion is audible as added harmonics and a gritty, edgy, harsh or fuzzy character: the sound is dirtier and often louder and more aggressive than a clean tone, with extra high-frequency content created by clipping the waveform. Compression is audible as a controlled, even dynamic level: the loud and quiet parts are closer together, the sound is consistent and often sounds denser, punchier or more sustained, and at heavy settings you may hear the level pumping or breathing.
You would recognise a synthesised sound rather than a recorded one by features a real instrument does not have: perfectly steady, pure or electronic timbres, characteristic waveform tones (a buzzy sawtooth, a hollow square), filter sweeps, obviously artificial or evolving textures, and the lack of the natural variation, breath or room sound of an acoustic recording.
Markers reward distortion = added harmonics/gritty/harsh, compression = even/controlled dynamics (denser, possible pumping), and synthesis recognised by electronic/steady timbres, characteristic waveforms, filter sweeps and the lack of natural acoustic variation.
Related dot points
- Critical listening and audio analysis: identifying EQ, dynamics, effects, panning and synthesis by ear, describing what you hear in precise technical terms, linking an audible effect to the technique and the technology that created it, and answering Component 3 listening questions.
A focused answer to the Edexcel 9MT0 critical-listening content, covering identifying EQ, dynamics, effects, panning and synthesis by ear, describing them precisely, linking effect to technique to technology, and Component 3 questions.
- Analysing recordings in their technological context: recognising the era and technology of a recording from its sound, linking production features to the development of recording technology, comparing recordings across eras, and writing the extended analytical response.
A focused answer to the Edexcel 9MT0 contextual-analysis content, covering recognising the era and technology of a recording from its sound, linking production to the development of recording technology, comparing eras, and the extended response.
- Time-based effects (reverb and its parameters, delay and its types) and modulation effects (chorus, flanger, phaser, tremolo and vibrato), plus distortion, how each is generated, and the use of send and insert effects with the wet/dry balance.
A focused answer to the Edexcel 9MT0 effects content, covering reverb and delay, modulation effects (chorus, flanger, phaser, tremolo, vibrato), distortion, send versus insert effects and the wet/dry balance.
- Dynamics processing: the compressor and its parameters (threshold, ratio, attack, release, knee, makeup gain), gain reduction, limiting, the noise gate and expander, and creative uses such as controlling peaks, adding punch and parallel compression.
A focused answer to the Edexcel 9MT0 dynamics content, covering the compressor and its parameters (threshold, ratio, attack, release, knee, makeup gain), gain reduction, limiting, gating, and creative compression.
- Other synthesis methods: additive synthesis (building from sine waves), FM synthesis (carrier and modulator), wavetable synthesis, the characteristic sounds of each, and how they contrast with subtractive synthesis.
A focused answer to the Edexcel 9MT0 synthesis content, covering additive synthesis from sine waves, FM synthesis with carrier and modulator, wavetable synthesis, their characteristic sounds, and the contrast with subtractive synthesis.
Sources & how we know this
- Pearson Edexcel A-Level Music Technology (9MT0) specification — Pearson Edexcel (2017)