What's the advantage of a hardware synth?

[David Csercsics]

>I'm not visually impaired and I've not used a hardware synth myself,
>but I'm curious.  What is the advantage of a hardware synth over a
>software synth?
>
>I can think of a few possibilities, but I'm curious which are true and
>are important for those who use or prefer hardware synths:
>
>1.  It doesn't affect the computer's sound system, which can therefore
>play other sounds unaffected by the TTS.  This could probably be
>achieved for a software synth by using two sound cards.

Not that easily since you'd have to use 2 sets of speakers or a mixer
which could be done but would be a bit awkward. Using headphones for
speech and putting other stuff through speakers would be an option but
a hardware synth just takes care of all  that for you.

>
>2.  System startup messages can be spoken before the point when the
>sound system and synth software is initialized and working.  This would
>be overcome by the proposed "Spoken Boot" feature.

Not entirely unless you propose to have the spoken boot feature speak every kernel message.

>
>3.  Problems with installing and setting up a software synth.
>

Yep. This is a big one. If you're using software speech only and the
software has a bug  or something that causes it not to work you can get
yourself into a situation where you have no speech. Having the kernel
handle the speech has the advantage that you know what's going on unless
the kernel is hosed which means that you would know that too. In the
case of gnome there are several things that could potentially cause you
to lose speech and if you're relying on software speech you can be in
a pickle. That said, speechd-up and speech-dispatcher seem to be quite
stable with espeak on my laptop which I cannot hook a hardware synth
to. So I can usually drop to a text console to fix things if gnome
screws up. There's also the issue of every live CD on the planet
detecting the wrong soundcard at boot so I have to crawl behind the desk
and temporarily use the onboard sound card to run things like the Ubuntu
live CD. There should be a boot option to force the module of your choice
to be used for sound. We also run into the issue that gnome doesn't seem
to let you use multiple sound sources for different things.

>4.  Prefer the sound of the hardware synth voice to those currently
>available with software synths.

Yep. I really like the DoubleTalk voices! I'm sure others like their
favourite synth voices as well. I like the ESpeak voice too but it
doesn't speak as fast as my DoubleTalk LT.

>
>5.  Limitations of computer processor power or memory, although I doubt
>this is an issue now.

Not much of an issue with something like Espeak but if you try to run
Festival on older hardware you'll hit huge processing issues.

>
>6.  The hardware synth offers some feature not available in the
>software synths.

Yep. Speed! Software synths don't speak or respond as fast as something
like a DoubleTalk. If your system is under load your speech will be
adversely affected since it's just another process. Also the kernel
preempt code doesn't play well with software speech so you add latency
to the system as a whole since you need to disable it for software
speech to work correctly.

This is about all I can think of right now but I may come up with
more later.