No.

More correctly: depends what you mean. Ruby is just a programming
language. There is no current setup for Ruby to run like Java Applets
(AFAIK) and actually execute an application in the web browser, which
is fundamentally different than the way most webpages work. (With
javascript being the weirdo between the two worlds). That's the only
way a webpage is going to be able to "record sound". Otherwise,
webpages just show information and handle formatting. All A/V stuff
within a webbrowser is just a trick.

You'd need a Java Applet. But, if you *really* wanted it to be in Ruby,
you could perhaps compile from Ruby to Java and with a little salt, hot
sauce, and love turn it into an applet.

-hampton catlin.