A sound card was developed in the late 80s for use with MacWorks.
It was functional but wasn't able to fully reproduce the Macintosh sound hardware, so it is not compatible with all sound generating software, and some software's sounds are distorted but recognizable.
Sound could be routed to the Lisa's internal speaker or connected to an external amplifier & speaker.
A working board has an EPROM in the U9 socket (not shown in the pic below).
The two rows of single row sockets (J2) are connected to the Lisa's expansion slot connector, they don't serve a specific function for the DAC.
(for future use)
Dr. Helmut Post sent me this picture of his LisaDAC SN#00043 ca. 2005
Regarding the LisaDAC/SCSI V2.0 EPROM label: apparently Daris Nevil had prototyped a SCSI port that piggybacked on the J2 socket headers, but as far as we know, none were produced.