"A register is a variety of a language used for a particular purpose or in a
particular social setting,"
[Source: Wikipedia "Register_(sociolinguistics)"]
Frozen register tends to refer to language use that is static (unchanging) each
time it is expressed.
Interpreting can be thought of as an act of "changing" a language from one form
to another.
Question: "If something is frozen in either English or ASL and then
interpreted to the other, is it still frozen in the new language?"
Response: If something originates as "frozen" in one language it can be
the basis for either frozen or not-frozen language usage in the target language.
The interpreted version "can be" frozen if you choose to freeze it via recording
and convincing people in the target culture to not make changes to the
interpretation.
If you start with a frozen form (video recording, audio recording, printed page,
protected PDF file, etc) and interpret it into a typically non-frozen form,
(signing that isn't video recorded, speaking that is not audio-recorded, or
writing that is done in the sand at a beach) then you are facing an "iteration
fidelity" problem wherein you are going to encounter difficulty maintaining the
"form" of your message in the new language (which is another way of saying "thaw
out" and start changing).
If you start with a frozen form of L1 (your source language) such as a video
recording of sign language and interpret it into a frozen form in your L2 (the
target language) such as an audio recording of spoken English -- then it is much
more likely that the message will be able to remain frozen in the new language.
Consider how Sacrament Prayers are handled at some Deaf Churches: The signer
pulls out a video display device, presses play, and then signs the prayer while
watching a model of the prayer being signed on the monitor. Then, for the
Hearing members in the audience an interpreter watches the signed prayer while
also occasionally glancing down at a card with the printed words of the prayer.
The Deaf signer is basing his/her signing on the "frozen" signing done on the
video while the Hearing interpreter is using the "frozen" printed form of the
prayer to guide his/her voiced interpretation. Thus the "physically frozen"
forms of the language help maintain the fidelity of "expressed" forms of the
language.
Notes:
Some examples of "frozen register" in ASL include Deaf School "fight songs,"
popular video recorded ASL poems, video recorded traditional prayers at Deaf
churches, and the video "The Preservation of Sign Language" by George W. Veditz
-- which is a "two-minute film featuring George W. Veditz, onetime president of
the National Association of the Deaf (NAD) of the United States, demonstrating
in sign language the importance of defending the right of Deaf people to their
language," [See: https://www.youtube.com/watch?v=XITbj3NTLUQ].