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D Mapes-Riordan

Publications and source records attributed to D Mapes-Riordan.

2 recordsLinked to original sources

Loudness recalibration as a function of level.

Recent research on loudness has focused on contextual effects on loudness, both assimilation and recalibration. The current experiments examined loudness recalibration [Marks, J. Exp. Psychol. 20, 382-396 (1994)]. In the first experiment, an adaptive tracking procedure was used to measure loudness recalibration as a function of standard- and recalibration-tone level. The standard-tone frequencies were 500 and 2500 Hz and the levels were 80-, 70-, 60-, and 40-dB SPL, and threshold. Seventeen dB of loudness recalibration was obtained (combined over both frequencies) in the 60-dB SPL condition. This amount of loudness recalibration, while substantial, is still less than that obtained by Marks (22 dB), using the method of paired comparisons. The second experiment sought to duplicate Marks' earlier experiment [Marks, J. Exp. Psychol. 20, 382-396 (1994), experiment 2]. The results of this experiment (21 dB) were almost identical to those obtained by Marks. The results of experiment 1 indicate that loudness recalibration is maximum when the recalibration tone is moderately louder than the subsequent standard tones. Relatively little loudness recalibration is exhibited when the standard-tone level equals the recalibration-tone level. In addition, there is no loudness recalibration at threshold. The tracking procedure also identified that the onset of loudness recalibration is very rapid. The difference between the maximum loudness recalibration obtained at each frequency (11 dB at 500 Hz, 6 dB at 2500 Hz) suggests that loudness recalibration is dependent upon the frequency of the standard tone.

Acoustic Stimulation↗

The relationship between localization and the Franssen effect.

The relationship between localization and the Franssen effect was studied for noise and tones in a sound-deadened and in a live room. The noise was wideband and the tones were 250, 500, 1000, 1500, 2500, and 4000 Hz. Listeners were asked to determine the location of the stimuli in a localization task and to discriminate the difference between a pair of stimuli used to generate the Franssen illusion and a steady-state tone in a Franssen-effect discrimination task. Poor performance in the Franssen-effect discrimination task is consistent with the stimulus conditions leading to a strong Franssen illusion. Poor performance in both the Franssen effect and localization tasks was obtained for midfrequency tones (near 1500 Hz) and in the live room. Thus, the Franssen illusion is strongest for a live room and for midfrequency tones consistent with the difficulty listeners have in localizing sounds under these conditions. These results are consistent with those of Hartmann and Rakerd [J. Acoust. Soc. Am. 86, 1366-1373 (1989)] and support their suggestion of a correlation between the Franssen effect and localization in rooms.

Amplifiers, Electronic↗