You can start the irb
or console attaching the --noecho
option.
$ irb --noecho
2.0.0p353 :001 > true
2.0.0p353 :002 >
Otherwise, if the console was started by another process, simply set conf.echo = false
$ irb
2.0.0p353 :001 > true
=> true
2.0.0p353 :002 > conf.echo = false
2.0.0p353 :004 > true
2.0.0p353 :005 >