Abstract
Temporal integration for loudness of 5-kHz tones was measured as a
function of level between 2 and 60 dB SL. Absolute thresholds and
levels required to produce equal loudness were measured for 2-,
10-, 50- and 250-ms tones using adaptive, two interval, two
alternative forced choice procedures. The procedure for loudness
balances is new and obtained concurrent measurements for ten tone
pairs in ten interleaved tracks. Each track converged at the level
required to make the variable stimulus just louder than the fixed
stimulus. Thus, the data yield estimates of the just noticeable
difference for loudness level andtemporal integration for
loudness. Results for four listeners show that the amount of
temporal integration, defined as the level difference between
equally loud short and long tones, varies markedly with level and
is largest at moderate levels. The effect of level increases as
the duration of the short stimulus decreases and is largest for
comparisons between the 2- and the 250-ms tones. The
loudness-level jnds are also largest at moderate levels and,
contrary to traditional jnds for the level of two dual-duration
tones, they do not appear to depend on duration. The latter
finding indicates that loudness discrimination between stimuli
that differ along multiple dimensions is not the same as level
discrimination between stimuli that differ only in level. An
equal-loudness-ratio model, which assumes that the ratio of
loudnesses for a long and a short tone at equal SPL is the same at
all SPLs, can explain the level dependence of temporal integration
and the loudness jnds. It indicates that the loudness function
(log(loudness) versus SPL) is flatter at moderate levels than at
low and high levels in agreement with earlier findings for 1-kHz
tones [M. Florentine et al., J. Acoust. Soc. Am. 99, 1633-1644
(1996)].
Original language | English |
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Journal | Acoustical Society of America. Journal |
Volume | 101 |
Issue number | 2 |
Pages (from-to) | 669-680 |
ISSN | 0001-4966 |
DOIs | |
Publication status | Published - 1997 |