Auditory Bilateral Stimulation

Auditory bilateral stimulation delivers short tones that alternate between the left and right ear through headphones or stereo speakers. It is used when clients prefer to close their eyes, when eye tracking is uncomfortable, or in combination with visual BLS for added intensity.

Comparative studies have found auditory BLS produces reprocessing effects comparable to visual BLS in many contexts, consistent with the working-memory account: any well-delivered dual-attention task taxes working memory during recall.

For clinical use, auditory BLS requires: true stereo output (headphones strongly recommended online), a tone frequency the client finds neutral or pleasant, and consistent pan depth. BilateralSync generates tones in the browser with adjustable frequency, volume and panning depth, keeping perfect sync with the visual target when both modalities are used together.