Pure-Tone Equal Loudness Contours for Standard Tones of Different Frequencies

It is widely assumed, based on Chocholle's (1940) research, that stimuli that appear equal in loudness will generate the same reaction times. In Experiment 1, we first obtained equal-loudness functions for five stimulus frequencies at four different intensity levels. It was found that equal loudness produced equal RT a~80 phons and 60 phons, but not at 40 phons and 20 phons. It is likely that Chocholle obtained equivalence between loudness and RT at all intensity levels because of relay-click transients in his RT signals. One main conclusion drawn from Experiment 1 is that signal detection (in reaction time) and stimulus discrimination (in loudness estimation) require different perceptual processes. In the second phase of this investigation, the RT-intensity functions from six different experiments were used to generate scales of auditory intensity. Our analyses indicate that when the nonsensory or "residual" component is removed from auditory RT measures, the remaining sensory-detection component is inversely related to sound pressure according to a power function whose exponent is about -.3. The absolute value of this exponent is the same as the .3 exponent for loudness when interval-scaling procedures are used, and is one-half the size of the .6 exponent which is commonly assumed for loudness scaling.The historic traditions that underlie the present research are formidable. Psychophysicists have consistently found a direct relation between auditory stimulus intensity and loudness. Specifically, Stevens and his colleagues have established that perceived loudness grows as a power function of stimulus intensity (Marks, 1974(Marks, , 1979. Equally impressive is the evidence in support of an inverse relation between stimulus intensity and simple auditory reaction time (RT). Classic experiments by Cattell (1886), Chocholle (1940), Pieron (1920), and Wundt (1874) have convincingly shown that RT decreases monotonically with corresponding increases in auditory stimulus intensity.Based on the fact that stimulus frequency, along with stimulus intensity, are the primary determinants of both loudness and RT, the present paper comprises two major sections in which these two stimulus attributes are evaluated. First, we evaluated the relation between equal loudness (across frequencies) and RT, using Chocholle's (1940) attempted to synthesize the data from several RT experiments in order to construct a uniform scale of sensory intensity that is based on RT measures. PHASE 1: EQUAL LOUDNESS AND REACTION TIMEIt is remarkable how many investigators have cited Chocholle's research, conducted over 40 years ago at the Sorbonne Laboratory, as the definitive study of the relation between auditory RT and signal intensity and frequency. His experiments were extensive but simple in design. Three experienced subjects generated RT-intensity functions over a wide range of intensity levels for frequencies of 20, 50, 250, 500, 1,000, 2,000, 4,000, 6,000, and 10,000 Hz. From these initial results, he drew "equal-RT" contours; that is, stimul...

Section: Resultscontrasting

confidence: 43%

Loudness and reaction time: I

Kohfeld

Santee

Wallace

1981

“…For example, when subjects are asked to give magnitude estimates of the loudness of tones that vary in frequency and intensity (Schneider, Wright, Edelheit, Hock, & Humphrey, 1972), equal loudness contours constructed from these judgments are consistent with equal loudness contours constructed from direct sensory matches of tones at different frequencies (Molino, 1973;Ross, 1967). Moreover, both magnitude estimation techniques and nonmetric scaling of loudness differences agree in this regard (Schneider & Bissett, 1987).…”

mentioning

confidence: 73%

Does stimulus context affect loudness or only loudness judgments?

Schneider

Parker

1990

Marks (1988) reported that when equal-loudness matches were inferred from magnitude estimates of loudness for tones of two different frequencies, the matches were affected by changes in the stimulus intensity range at both frequencies. Marks interpreted these results as reflecting the operation of response biases in the subjects' estimates; that is, the effect of range was to alter subjects' judgments but not necessarily the perception ofloudness itself. We investigated this effect by having subjects choose which oftwo tone pairs defined the larger loudness interval. By using tones of two frequencies, and varying their respective intensity ranges, we reproduced Marks' result in a procedure devoid of numerical responses. When the tones at one frequency are all soft, but the tones at the other frequency are not all soft, cross-frequency loudness matches are different from those obtained with other intensity range combinations. This suggests that stimulus range affects the perception of loudness in addition to whatever effects it may have on numerical judgments of loudness.

“…At higher intensities, the contours below 1000 Hz flatten out considerably, but by an amount that varies over a range of 40 dB or so across the studies mentioned above. Finally, the separation of the contours also depends on several factors, and especially on the standard frequency (Molino, 1973). Thus, although there does exist an ISO standard set of equal-loudness contours, based on a 1000-Hz standard, this standard is not usually obtained in actual laboratory investigations.…”

Section: Equal-loudness Contoursmentioning

confidence: 99%

“…In a later paper, Schneider and Bissett (1987) used yet another method, comparison of loudness intervals across frequencies, to generate equal-loudness contours. Finally, Molino (1973) investigated the effects of standards of different frequencies on both equal-loudness contours and the properties of the loudness matches on which they were based.…”

Section: Equal-loudness Contoursmentioning

confidence: 99%

“…Figure 3 displays the equal-loudness contours calculated from the cross-frequency loudness matching functions shown in Figure 1 and 2. The 100Q-Hz frequency was taken as the standard, as is common practice (but see Molino, 1973). The intensities of each of the other frequencies needed to match the canonical intensity at 1000 Hz were then calculated either directly from the matching function (equation of best fitting straight line shown in Figure 1 or Figure 2) for that frequency and 1000 Hz (100, 200, 1100, and 9000 Hz) or indirectly from the matching function of that frequency and another that was directly matched to 1000 Hz (65, 250, and 10000 Hz).…”

Section: Equal-loudness Contoursmentioning

confidence: 99%

See 1 more Smart Citation

Critical bands and mixed-frequency scaling: Sequential dependencies, equal-loudness contours, and power function exponents

Ward

1990

Stimuli of random intensities and various but predictable frequencies were presented for repeated magnitude estimations on the same scale (mixed-frequency scaling). The frequencies for a particular judgment session were selected so that they lay either inside each other's critical bands or outside them. Contrastive dependencies of current magnitude estimation responses on previous stimuli of a different frequency were significantly affected by whether the two frequencies were inside or outside each other's critical bands, while assimilative dependencies were not. This reinforces the idea that such dependencies are sensory in nature and arise from a different mechanism than do the assimilative dependencies. Mixed-frequency scaling of loudness also gives rise to cross-frequency matching functions from which equal-loudness contours can be calculated. These contours calculated from the present judgments are similar to those produced from other methods, even when they are extrapolated to untested intensities. Power function exponents for loudness scaled in this way are larger for lower frequencies, as has been found in previous studies, and are consistent with the flattening of the calculated equal-loudness contours for low frequencies as intensity increases.