p5.speech set default voice is not working - p5.js

Question

Hello I am working with p5.speech and I have set in my code a default voice to an english voice like so:
var speech = new p5.Speech('Kate');
My computer default language is Italian, and everything works as it should. I hear the english voice. I tested it on a friend computer and he gets his Spanish default speaking voice. How is this possible? Do I need some more settings?

Answer 1

Voices available to different browsers, operating systems, individual computers are vastly different. Your friend's computer probably does not have a voice named Kate.
These are voices available to Chrome on my Win10 machine.
These are voices available to Edge on my Win10 machine.
These are voices available to Chrome on my MacBook Pro.
It's less likely that people will have a specific English voice named Kate; it's more likely that people will have at least one en-US voice. The following code can choose an English (United States) voice for you.
var speech = new p5.Speech();
speech.setLang("en-US");
Demo:
https://glitch.com/~p5-speech-setlang-setvoice
A demo for you to try different combinations of setLang() and setVoice()
My observations:
Voices available depend on the browser you use. For example, I have 21 voices in Chrome and 6 in Edge.
There are two related functions: setVoice() and setLang(). They digest different arguments.
setLang() will try to choose a voice in the language you want if you have never called setVoice(). If you have called setVoice() once, setLang() won't be able to change voice for you anymore.
setLang()
For example:
setLang("it-IT")
setLang("en-US")
setLang("en-GB")
setLang("es-ES")
setVoice()
For example:
setVoice("Microsoft David Desktop - English (United States)")
setVoice("Microsoft Zira Desktop - English (United States)")
setVoice("Google US English")
setVoice("Google UK English Female")
References: BCP-47 code for languages | p5.speech reference