Growth of loudness at 1000 and 3000 Hz

Loudness growth at 1000 and 3000 Hz was measured directly by magnitude estimation and production, and indirectly by loudness matches between tone and wide-band noise and by interfrequency matching. The outcome of the three series of experiments does not reveal any systematic difference in shape of the loudness curves at 1000 and 3000 Hz. To a first approximation, above about 30 dB SL the loudness functions at 1000 and 3000 Hz are power functions of sound pressure with an exponent close to the accepted ISO standard of 0.60 (0.30 re sound intensity). Below 30 dB SL both loudness curves become progressively steeper than a simple power function and approach the same limiting slope, re sound intensity, of unity. Consistent with Steven’s calculation system [J. Acoust. Soc. Am. 51, 575–601 (1972)], the data also show that loudness equality is achieved when a 3000-Hz tone is about 8 dB below the SPL of a tone at 1000 Hz. Subject Classification: [43]65.50, [43]65.75.