The first error was a very reduced in-house pre-validation after the
setup of the recording hardware and procedures. Because of this sloppy
procedure it went unnoticed that the same
prompts were displayed in both recording rooms. According to
the specification however, the prompts had to differ. This error was
not even detected in the final validation but was discovered by the
client after the first delivery. It is very likely that a proper
pre-validation by an external partner (or the client) might have
detected this logistical error much earlier thus saving a
considerable amount
of manpower and money (see section for
details about pre-validation).
The second error was of a technical nature. Although the pre-validation
was performed on both recording setups in the two recording rooms and
showed valid recordings, it turned out in the final validation
that in one of the recording rooms the input selection was
later unintentionally set to another channel and all recordings were in fact
empty. A number of speakers had to be contacted again and asked for an
additional recording session to fill up the missing data. This error could
easily have been detected very early if quality control in form of random tests on the
recorded data had been performed (for details about quality control refer to section ).