  Triggered ion-acoustic waves are a pair of coupled waves observed in the
previously unexplored plasma regime near the Sun. They may be capable of
producing important effects on the solar wind. Because this wave mode has not
been observed or studied previously and it is not fully understood, the issue
of whether it has a natural origin or is an instrumental artifact can be
raised. This paper discusses this issue by examining 13 features of the data
such as whether the triggered ion-acoustic waves are electrostatic, whether
they are both narrow-band, whether they satisfy the requirement that the
electric field is parallel to the k-vector, whether the phase difference
between the electric field and the density fluctuations is 90 degrees, whether
the two waves have the same phase velocity as they must if they are coupled,
whether the phase velocity is that of an ion-acoustic wave, whether they are
associated with other parameters such as electron heating, whether the electric
field instrument otherwise performed as expected, etc. The conclusion reached
from these analyses is that triggered ion-acoustic waves are highly likely to
have a natural origin although the possibility that they are artifacts
unrelated to processes occurring in the natural plasma cannot be eliminated.
This inability to absolutely rule out artifacts as the source of a measured
result is a characteristic of all measurements.
