SchoolDigger data sources: National Center for Education Statistics, U.S. Department of Education, the U.S. Census Bureau and the Minnesota Department of Education. IMPORTANT DISCLAIMERS: Not all boundaries are included. We make every effort to ensure that school and district boundary data are up-to-date.
The spectral sensitivity is typically expressed as a QE Curve, in which the probability to detect a photon of a particular wavelength is expressed as a percentage.So for example if one in every 10 photons is detected this is expressed as a QE of 10%. The curve for a typical CCD is shown in the diagram on the below:
How Praat makes spectral slices. 1  Praat offers two analysis methods: FFT and LPC. 2  FFT is easier to set up but is sensitive to fundamental frequency and so is less successful for higher pitched voices.  LPC is not sensitive to fundamental frequency but the settings need to be carefully tuned for each speaker.