Panning Variations — User Guide

Create stereo motion from a mono working source using sweeps, sine-based auto-pan, ping-pong motion, stochastic random walk, expanding or contracting motion, static placement, or equal-channel tremolo.

Author: Shai Cohen Affiliation: Department of Music, Bar-Ilan University, Israel Version: 0.4.2 (2026) Praat

Contents:

What this does Quick start Panning patterns Panning laws Parameters Processing pipeline Visualization

What this does

Panning Variations creates a two-channel output by first deriving a mono working source and then applying independent left/right gain automation. A mono input is copied; any input with more than one channel is converted to mono before panning. The original Sound is not modified.

10 patterns — two linear sweeps, sine auto-pan, double-rate sine auto-pan, ping-pong, random walk, expanding/contracting sine auto-pan, tremolo, and static position.
Two panning laws — constant-power trigonometric panning or linear panning.
Bounded pan range — Min_pan and Max_pan are clamped to [0,1] and sorted if entered in reverse order.
Automation through IntensityTier — sampled L/R gain curves are converted to dB tier points and multiplied with two copies of the mono source.
Stereo output — the two automated channels are combined and normalized to peak 0.99.

Important input behavior: stereo and other multichannel inputs are not spatially remixed in their original form. They are first downmixed to mono, then re-panned as a new stereo signal.

Quick start

Select exactly one Sound.
Run Panning_variations.praat.
Choose a Panning_pattern.
Set Min_pan and Max_pan to define the allowed stereo range.
For cyclic pan patterns, set Number_of_cycles. For Tremolo, set Motion_speed_(Hz).
Choose constant-power or linear panning, then run the script.

Output naming: the result is named original_pan_pattern, for example voice_pan_SinePan or voice_pan_Random.

Panning patterns

Pattern	Motion	Active motion parameter	Output suffix
Linear Sweep (L → R)	One linear traversal from the low end of the selected pan range to the high end across the full Sound duration.	None	`SweepLR`
Linear Sweep (R → L)	One linear traversal in the opposite direction.	None	`SweepRL`
Sine Auto-Pan	Sinusoidal motion across the selected pan range.	`Number_of_cycles`	`SinePan`
Double-Rate Sine Auto-Pan	The same sine trajectory at twice the ordinary sine rate. With Number_of_cycles = 2, four sine cycles occur across the Sound.	`Number_of_cycles`	`DoubleSinePan`
Ping-Pong (bounce)	Triangle-wave motion that repeatedly travels between the two ends of the selected pan range.	`Number_of_cycles`	`PingPong`
Random Walk	Stochastic position/velocity walk with damping and edge reflection, then mapped into the selected pan range.	Neither Speed nor Cycles	`Random`
Expanding Sine Auto-Pan	Starts at the centre of the selected range and gradually increases sine excursion toward the full range.	`Number_of_cycles`	`ExpandPan`
Contracting Sine Auto-Pan	Starts with full-range sine excursion and gradually contracts toward the centre.	`Number_of_cycles`	`ContractPan`
Tremolo (both channels)	No left/right motion in the audio. L and R receive the same sinusoidal gain from 0 to 1.	`Motion_speed_(Hz)`	`Tremolo`
Static Position	Fixed pan value mapped through the selected Min/Max range.	`Static_position`	`Static`

Random Walk is intentionally non-reproducible in the current form. The script uses Praat random draws but exposes no seed control. Curve_resolution also affects the number and temporal spacing of random-walk updates.

Panning laws

Constant-power panning

angle = pan × π/2
L = cos(angle)
R = sin(angle)

This keeps L² + R² = 1 before the later peak normalization.

Linear panning

L = 1 - pan
R = pan

At the centre, both channels are 0.5 before final normalization.

For all panning patterns except Tremolo, Use_constant_power selects between these laws. Tremolo bypasses the pan-law gain calculation and sets both channels to the same tremolo value.

Near-zero floor: before conversion to IntensityTier dB, gains below 0.001 are raised to 0.001. Therefore a nominal hard-left or hard-right position leaves the opposite channel at approximately −60 dB relative to unity rather than mathematical zero.

Parameters

Parameter	Default	Actual behavior
Panning_pattern	Linear Sweep (L → R)	Selects one of the 10 patterns above.
Motion_speed_(Hz)	1.0	Used by Tremolo. Sweeps, Static, Random Walk, and cycle-based pan patterns do not use it.
Number_of_cycles	2.0	Used by Sine Auto-Pan, Double-Rate Sine Auto-Pan, Ping-Pong, Expanding Sine Auto-Pan, and Contracting Sine Auto-Pan.
Min_pan	0.0	Lower endpoint of the allowed pan range. Clamped to [0,1].
Max_pan	1.0	Upper endpoint. Clamped to [0,1]. If Min exceeds Max after clamping, the two are swapped.
Static_position	0.5	Normalized position used by Static mode before mapping through the Min/Max range; final pan is clamped to [0,1].
Curve_resolution	200	Number of automation intervals. The script creates resolution + 1 tier points over the Sound duration.
Use_constant_power	yes	Selects constant-power vs. linear gain law for panning modes. It does not affect Tremolo audio.
Draw_visualization	yes	Draws pan position, actual L/R automation gains, output waveform, and summary.
Play_result	yes	Plays the completed stereo Sound.

Processing pipeline

1. Require exactly one selected Sound.
2. Read duration, sample rate, and channel count.
3. Clamp/sort Min_pan and Max_pan.
4. Convert multichannel input to mono, or copy mono input.
5. Sample the selected motion at Curve_resolution + 1 times.
6. Map each pan value into the Min/Max range and clamp to [0,1].
7. Calculate L/R gains; Tremolo instead assigns one equal gain to both channels.
8. Floor gains at 0.001 and convert them to IntensityTier dB values around Praat's 70 dB unity reference.
9. Multiply two mono copies by the left and right tiers.
10. Combine them to stereo.
11. Apply Scale peak: 0.99 unconditionally.
12. Remove intermediate objects and optionally draw/play the result.

Normalization behavior: Scale peak: 0.99 is full peak normalization, not merely a clipping ceiling. It can either attenuate or amplify the completed result so that its absolute peak becomes 0.99.

Visualization

When Draw_visualization is enabled, the script draws four process-focused regions:

Pan Position — the sampled pan trajectory over time, with L/C/R reference lines and the selected Min/Max band.
L/R Gain — the actual automation gains stored for the IntensityTiers. In Tremolo, Left and Right therefore coincide as equal modulation curves.
Output — waveform preview of the completed stereo Sound after normalization.
Summary — pattern-specific active control, pan range where relevant, constant-power state, and duration.

Tremolo display: its Pan Position curve remains fixed at the mapped centre because Tremolo is not spatial motion; the meaningful motion appears in the L/R Gain panel, where both gains move together.

Practical use

Sweeps and ping-pong

Use for clear left/right gestures, transitions, alternating motion, and spatial articulation of mono material.

Sine auto-pan

Use cycle count to define repeated periodic motion over the exact Sound duration rather than an independent Hz rate.

Expanding / contracting

Useful when the stereo excursion itself should evolve over time while retaining a sine trajectory.

Random Walk

Creates a different stochastic pan path on each run; use a narrower Min/Max range when full-width wandering is too extreme.

Tremolo

Applies equal amplitude modulation to both output channels. It is included in the tool as a gain-variation mode, not a panning trajectory.

Static Position

Places the mono working source at one fixed stereo position using the same selected pan law as the moving panning modes.