Audio S1. The original Laurel/Yanny audioclip. Note that many people do not exactly hear Yanny, but analogue forms such as Yari, Yelli, Yawee, etc.
Audio S2. A lowpass filtered version, usually biased toward Laurel.
Audio S3. A highpass filtered version, usually biased toward Yanny.
Audio S4. A sequence going from lowpass to highpass (see Fig. 1A). Because of context effects, the percept of Laurel may persist for sounds that would have been heard as Yanny in isolation.
Audio S5. As S4, but in reverse order.