/etc/asterisk/dsp.conf is in asterisk-config 1:1.8.10.1~dfsg-1ubuntu1.
This file is owned by root:root, with mode 0o640.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | [default]
;
; Length of sound (in milliseconds) before a period of silence is considered
; to be a change from talking to silence or a period of noise converts silence
; to talking. [default=256]
;
;silencethreshold=256
|