alt-Blumlein shuffling demonstrations

Improved Localization for Binaural Recordings and Stereo Program Material Using ‘Blumlein Shuffling’

Institute of Acoustics’ Reproduced Sound 2025

Author

Affiliation

Jonathan J Digby

University of Derby

Published

March 8, 2026

Instructions

Loudspeakers
Please ensure you are using a pair of loudspeakers in the standard two-channel stereo configuration.
Ideally, you will be positioned approximately equidistant with two loudspeakers: Left(1) and Right(2).
All equalization, loudness, and spatial processing should be bypassed, off, or disabled.
Built-in PC loudspeakers are not suitable for these demonstrations.

Earphones (optional)
Please ensure you are using a pair of earphones in the standard two-channel stereo configuration.
All equalization, loudness, and spatial processing should be: bypassed, off, or disabled.

Important: Before continuing put your volume control to its lowest level setting.

Loudness Calibration

If you prefer to skip this step please scroll directly to Audio demonstrations

After adjusting your volume level to a minimum, press
Press to Stop the looped audio

Slowly increase your volume level until the low- and high-pitched noise bursts are at the same level (equally loud).
You may notice that changing the overall listening level affects the loudness of the two noise bursts at different rates.
You can continue to adjust the volume level (up and down) until both high- and low-pitched noise bursts are well balanced; or thereabouts.
STOP IMMEDIATELY if the noise bursts are too loud.

Loudspeakers calibration signal

Earphones calibration signal

If you are unable to match the loudness of the noise bursts before the volume is too high, please discontinue the calibration.
You could try using different listening devices.
Please continue

Audio demonstrations

Excerpts from concert recordings using a baffled near-coincident microphone array.
There are two versions of each snippet: A and B.

A – earphones version: unprocessed version — suitable for direct reproduction using earphones.

B – loudspeakers version: alt-Blumlein shuffled version — intended for two-channel ‘stereo’ loudspeakers (binaural illusion or binaural effect).

Please wait for each item to complete, or press to Interrupt playback.
Audio will not automatically switch after selecting the next clip.

If you have completed the Loudness Calibration there is no need to adjust your volume control;
however, feel free to adjust your volume control to a preferred listening level.

At the bottom of the page is a list of credits.

The entire collection will usually take less than 5 minutes.
Have fun.