title: A comparison of t test, F test, and coherence methods of detecting steady-state auditory-evoked potentials, distortion-product otoacoustic emissions, or other sinusoids.
abstract: Sinusoids in background noise can conveniently be detected using unsegmented power spectra, comparing power at the signal frequency to average power at several neighbor frequencies. In this case, the F test is preferable to t tests based on rms or dB values, because of the skewed distributions of rms and dB when signal-to-noise ratio (SNR) = 0. F-test performance improves as the number of frequencies increases, to about 15, but can be degraded if the background noise is not white, with a slope exceeding about 10 dB for the range of frequencies sampled. Segment analysis, using magnitude-squared coherence (MSC) or related statistics, has equivalent statistical power; MSC and F each yield unbiased SNR estimates that have identical distributions when SNR = 0. Selection of F or MSC for detection of sinusoids will usually be a matter of convenience.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Texas Health Science Center, San Antonio 78284-7777, USA. dobie@uthscsa.edu
authors.forename: R A
authors.initials: RA
authors.lastname: Dobie
authors.forename: M J
authors.initials: MJ
authors.lastname: Wilson
mesh_terms: D005072:Evoked Potentials, Auditory; D008962:Models, Theoretical; D009622:Noise; D010469:Perceptual Distortion