Showing papers by "Murray B. Sachs published in 1976"

Two-tone suppression in auditory-nerve fibers: extension of a stimulus-response relationship.

Abstract: Average discharge rate of single auditory‐nerve fibers in cats was measured in response to one‐ and two‐tone stimuli. One component (the ’’suppressor tone’’) of each two‐tone stimulus was at a frequency (f2) which produced two‐tone suppression at some stimulus levels. The other component (excitor tone) produced an increase in rate above the spontaneous rate when presented alone. Fractional response was defined as the driven rate to the two‐tone stimulus divided by the driven rate to the excitor alone. Fractional response is thus a quantitative measure of the amount of suppression produced by a suppressor tone. A number of qualitative differences were found in the dependence of fractional response for f2≳CF and f2

Differential sensitivity to frequency and intensity in songbirds

Abstract: Frequency‐ and intensity‐difference limens were measured in two passerine species, the red‐wing blackbird (Agelaius Phoeniceus) and the brown‐headed cowbird (Molothrus Ater). Operant conditioning techniques which we described previously were employed. The techniques made use of key pecks as observing and report responses. Birds were reenforced with food for reporting changes in frequency or intensity in an ongoing train of tone bursts. Smallest Weber fractions were obtained at 4 kHz where the mean JND was 30 Hz or Δf/f=0.0075. The mean value of Δf/f was 0.015 at 1 kHz and 0.02 at 8 kHz. Birds were more sensitive to upward frequency shifts than to downward shifts at 1 and 2 kHz. Mean intensity JND's were 2.5 dB for a 1‐kHz tone at 50 dB SL and 5.4 dB for a 20‐dB‐SL tone. [This work was supported by a grant from NINCDS.]