> However, in a phenomenon called electron fractionalization, in certain materials an electron can be broken down into smaller "charge pulses," each of which carries a fraction of the electron's charge.
> The experiment reveals that, when a single electron fractionalizes into two pulses, the final state cannot be described as a single-particle state, but rather as a collective state composed of several excitations.
Doesn't that make the breaking of electrons into e/2 supposed to be an emergent property then?

Do the "pitch" of ultrasound, if we can hear it, depends on frequency?

According to this paper https://www.jstage.jst.go.jp/article/ast/34/6/34_E1307/_pdf/-char/en, no matter how high or low the frequency of the ultrasound, the resulting pitch is always lower than it would supposed to be. Does that means there are particular frequency ranges where abnormalities will occur such as especially around the sub bass frequency region (around 5 hz or a little bit more) there will be no sound produced but rather the perception of those very low sounds is we feel them but not hear them?