This collection contains the following files:

• README.TXT ==> this file
• CHIRP.EXE ==> DOS program to calculate chirp signals
• GNUPLOT.EXE ==> DOS program to plot (e.g. chirp signals)
• GNUPLOT.GIH ==> help file for GNUPLOT.EXE
• CHIRP ==> example chirp, ready for usage in ILO 88 and ILO 92
• mk_chirp.m ==> matlab script to calculate the chirp
• mk_chirp_spec ==> matlab script to calculate a spectrum for mk_chirp
• CHIRP.ZIP ==> all files above zipped in one file

The program CHIRP.EXE allows to calculate chirp signals and outputs them in vaious formats (including ascii and binary)

Some hints for the use with the ILO machine (ILO 88 or ILO 92): choose ilo-linear or ilo-nonlinear as output format

• choose 25000 Hz as sampling rate
• choose 500 Hz to 6000 Hz for wide band stimulation
• choose 500 as amplitude
• you may choose the greenwood map to generate a stimulus that attempts to stimulate each hair cell with the same aount of energy
• for the measurements with ILO the start of the window in the ILO program should be ajusted for proper artefact rejection since the peak of the stimulus is reached later

The program GNUPLOT.EXE can display the chirp signals. GNUPLOT was programmed by the free software foundation. CHIRP.EXE can create a suitable file GNU for the use of GNUPLOT. To display the chirp signals and their spectra, you can simply type GNUPLOT GNU. A second possibility is to start GNUPLOT and type load 'gnu' within GNUPLOT. Type help withing GNUPLOT to find out about GNUPLOT. If help does not work, set the environment variabel GNUHELP to the path of the file GNUPLOT.GIH.

In case of any trouble with the CHIRP program, don't hesitate to contact me via e-mail jne@oticon.dk

Joachim Neumann