Debian 12 speech-dispatcher with flite voices

I'm trying to use flite with speech-dispatcher, but I'm not fond of the 
kal16 voice. I'd much rather use slt. I looked at the flite.c source 
code at 
https://github.com/brailcom/speechd/blob/master/src/modules/flite.c and 
it appears to be loading only either 'kal' or 'kal16' based on a 
compiler flag setting. When I used apt to install flite, it came with 
'kal', 'awb_time', 'kal16', 'awb', 'rms' and 'slt'. Does anyone know if 
I have to compile a custom version of 
/usr/lib/speech-dispatcher-modules/sd_flite in order to use a different 
voice?

Thank you, -Aaron