TEMPORAL-MODULATION TRANSFER-FUNCTIONS BASED UPON MODULATION THRESHOLDS

被引:677
作者
VIEMEISTER, NF
机构
[1] Department of Psychology, University of Minnesota, Minneapolis
关键词
D O I
10.1121/1.383531
中图分类号
O42 [声学];
学科分类号
070206 ; 082403 ;
摘要
The detectability of amplitude modulation in the absence of spectral cues provides a quantitative description of temporal resolution for steady-state signals with relatively small amplitude changes. Modulation thresholds for sinusoidally amplitude-modulated wideband noise were measured as a function of modulation frequency. The resulting “Temporal Modulation Transfer Function” (TMTF) shows a lowpass characteristic for modulation frequencies below about 800 Hz. The lowpass characteristic is extended up to approximately 2 kHz when the increment in average power produced by modulation is eliminated. The important parametric effects are summarized as follows: (1) TMTFs are independent of overall level, except at very low intensities; (2) the time constant indicated by the TMTF decreases as the center frequency of the band-limited, modulated noise is increased; (3) modulation thresholds generally decrease with increasing duration of modulation, particularly at low modulation frequencies; (4) when the carrier is gated for the duration of modulation, the TMTF shows a highpass segment at low modulation frequencies. Although the TMTFs are not directly consistent with the attenuation characteristic of a simple lowpass filter, a model which incorporates such a filter, with a time constant of 2.5 ms, describes the entire TMTF and also describes the modulation functions obtained with square-wave and pulse modulation. The wide bandwidth of initial filtering indicated by the model raises the important question of the role of peripheral filtering in determining the detectability of high-frequency modulation. © 1979, Acoustical Society of America. All rights reserved.
引用
收藏
页码:1364 / 1380
页数:17
相关论文
共 50 条
[41]   MODULATION TRANSFER-FUNCTIONS AS QUALITY CONTROLS FOR AERIAL PHOTOGRAPHY [J].
WELCH, R ;
HALLIDAY, J .
PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING, 1973, 39 (03) :302-302
[42]   TEMPORAL-MODULATION SENSITIVITY OF MACAQUE MONKEYS [J].
MERIGAN, WH .
VISION RESEARCH, 1980, 20 (11) :953-959
[43]   MODULATION TRANSFER-FUNCTIONS OF GROUND-GLASS SCREENS [J].
KUTTNER, P .
APPLIED OPTICS, 1972, 11 (09) :2024-&
[44]   MEASUREMENT OF MODULATION TRANSFER-FUNCTIONS OF NEUTRON RADIOGRAPHIC SYSTEMS [J].
ALGER, DM ;
BULL, SR .
TRANSACTIONS OF THE AMERICAN NUCLEAR SOCIETY, 1975, 22 (NOV16) :145-146
[45]   MODELING IMAGER DETERMINISTIC AND STATISTICAL MODULATION TRANSFER-FUNCTIONS [J].
JOHNSON, JF .
APPLIED OPTICS, 1993, 32 (32) :6503-6513
[46]   NONLINEAR TEMPORAL-MODULATION OF PULSAR RADIOEMISSION [J].
CHIAN, ACL .
REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA, 1986, 12 :330-330
[47]   SPREAD FUNCTIONS AND MODULATION TRANSFER-FUNCTIONS OF FIBRE-OPTIC BUNDLES [J].
PLAYER, MA .
JOURNAL OF MODERN OPTICS, 1988, 35 (08) :1363-1372
[48]   IMPROVED FORTRAN PROGRAM FOR CALCULATING MODULATION TRANSFER-FUNCTIONS - REPLY [J].
NUSYNOWITZ, ML ;
BENEDETTO, AR .
JOURNAL OF NUCLEAR MEDICINE, 1977, 18 (07) :748-748
[49]   EFFECTS OF SURROUND ILLUMINATION ON TEMPORAL-MODULATION SENSITIVITY [J].
WISOWATY, JJ .
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA, 1979, 69 (10) :1486-1486
[50]   COMPUTED INTRINSIC EFFICIENCIES AND MODULATION TRANSFER-FUNCTIONS FOR GAMMA CAMERAS [J].
SVEDBERG, JB .
PHYSICS IN MEDICINE AND BIOLOGY, 1973, 18 (05) :658-664