Laurel or Yanny?

What if we stretch or compress the frequency spectrum (leaving pitch unchanged)?

This might cause you to hear "Yanny" at one extreme and "Laurel" at the other extreme.

Which sound is the boundary for you between "Laurel" and "Yanny"?

What if we also change the pitch?

Here are a few examples with pitch changed (F0 raised or lowered by 6 semitones).

Does the pitch shift affect your perception, or only the spectral shift?

Finally, just for fun, some extreme examples: pitch and spectrum both shifted by +/- 12 semitones.

CREDITS: All sounds were processed by Jackson Graves in MATLAB, using a software package called STRAIGHT, developed by Kawahara et al.: TANDEM-STRAIGHT: A temporally stable power spectral representation for periodic signals and applications to interference-free spectrum, F0 and aperiodicity estimation, by Hideki Kawahara, M. Morise, T. Takahashi, R. Nisimura, T. Irino and H. Banno, Proc. ICASSP'2008, Las Vegas, pp.3933-3936 (2008).