Hearing screening test is a method to determine the
disorder in human ears. Conventional audiometer and an
audiologist are required in order to perform the hearing screening
test. However, this procedure is difficult to be implemented
especially in a remote site such as factory or school due to the
ambient noise which may cause inaccuracy in the test. In this
work, the application of active noise control (ANC) is proposed to
reduce the ambient noise using a personal computer in hearing
screening test. The ANC algorithm was implemented using a
computer with data acquisition modules and LabVIEW software.
The results showed that the anti-noise was successfully generated
in the electrical domain but no reduction was observed in the
acoustic domain. The ANC is a deterministic application that
requires real-time operating system to respond to the input with
precisely timed output. In order to have an effective ANC system,
the processing time has to be less than 0.125 ms at 8 KHz
sampling rate.