Second formant transition discrimination
Joan Besing, John K. Cullen, Robert J. Porter, Randal Rampp, M. Jane Collins · The Journal of the Acoustical Society of America · 1987
The ability of listeners to process information conveyed by second formant transitions may be expected to be limited by their ability to detect differences in the rate of frequency change for the transition. To examine this question, difference limens (DLs) for initial transitions of isolated second formants were established using a four interval “same-different” procedure. These single formant signals were 300 ms in duration (60-ms transitions and 240-ms steady-state portions). The DLs for starting frequency, and thus rate of frequency change, were established for three standards which varied in rate and direction of transition; all had steady states at 1800 Hz. One standard had no transition and two had transitions of 2.5 Hz/ms that either fell from 1950 Hz or rose from 1650 Hz. The DLs were established for transitions with starting frequencies above and below each standard condition. The DLs for three of four experienced listeners were smaller for transitions in the frequency range above the steady state than for transitions in the frequency range below the steady state. Mean discriminable differences in starting frequency were 67 and 87.5 Hz in the frequency ranges above and below the steady state, respectively. [Supported by NINCDS and the Louisiana Lions Foundation.]