The psychophysics of absolute threshold and signal duration: A probabilistic approach

Abstract

The absolute threshold for a tone depends on its duration; longer tones have lower thresholds. This effect has traditionally been explained in terms of "temporal integration" involving the summation of energy or perceptual information over time. An alternative probabilistic explanation of the process is formulated in terms of simple equations that predict not only the time=duration dependence but also the shape of the psychometric function at absolute threshold. It also predicts a tight relationship between these two functions. Measurements made using listeners with either normal or impaired hearing show that the probabilistic equations adequately fit observed threshold-duration functions and psychometric functions. The mathematical formulation implies that absolute threshold can be construed as a two-valued function: (a) gain and (b) sensory threshold, and both parameters can be estimated from threshold-duration data. Sensorineural hearing impairment is sometimes associated with a smaller threshold=duration effect and sometimes with steeper psychometric functions. The equations explain why these two effects are expected to be linked. The probabilistic approach has the potential to discriminate between hearing deficits involving gain reduction and those resulting from a raised sensory threshold.

Time-frequency integration characteristics of hearing are optimized for perception of speech-like acoustic patterns

“…The alternative interpretation states that a longer stimulus provides more "opportunities" for the auditory system to detect it, and therefore it appears as if the auditory system performs integration in time (cf. Viemeister and Wakefield, 1991;Meddis and Lecluyse, 2011).…”

Towards a Unifying Basis of Auditory Thresholds: Binaural Summation

“…They include the nature of the look, the shape of the temporal window that defines a look, the possibility that successive looks might not be independent, and the nature and characteristics of the memory used to store the information from the looks. Moreover, the accumulation of information across looks still requires an integrator that operates over a long time (a point made by Meddis and Lecluyse 2011). Heil and Neubauer (2003) suggested another, physiologically plausible and simple, alternative to long-time-constant temporal integration.…”

“…Because the event probability increases with stimulus amplitude raised to an exponent, the amplitude required for a given performance (e.g., threshold criterion) decreases as stimulus duration increases. Meddis and Lecluyse (2011) formulated a similar probabilistic model of absolute threshold. However, it differs from that of Heil and Neubauer (2003) in important aspects.…”

Broadband noise exposure does not affect hearing sensitivity in big brown bats (Eptesicus fuscus)

“…The relatively long duration of these tones ensures concentration of energy at a single frequency, while in 3 ms FM sweeps, the effective duration of any one frequency is limited to about 100 μs. It is well known from mammalian psychoacoustics that detection thresholds vary with stimulus duration (Meddis and Lecluyse, 2011), particularly the sound's dwell-time at specific frequencies. On duration versus energy considerations alone, each of the tonal stimuli in Koay et al (1997) deliver up to 400 times more energy than each entire FM sound used in our experiments, for an expected threshold elevation of up to 26 dB for the FM sounds.…”