During the past decade a number of variations in the simple up‐down procedure have been used in psychoacoustic testing. A broad class of these methods is described with due emphasis on the related problems of parameter estimation and the efficient placing of observations. The advantages of up‐down methods are many, including simplicity, high efficiency, robustness, small‐sample reliability, and relative freedom from restrictive assumptions. Several applications of these procedures in psychoacoustics are described, including examples where conventional techniques are inapplicable.

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Transformed Up‐Down Methods in Psychoacoustics

Impedance audiometry was performed as part of the routine clinical examination in a consecutive series of more than 400 patients with various types and degrees of hearing impairment. An electroacoustic bridge (Madsen, ZO 70) was used to carry out the measurement of tympanometry, acoustic impedance, and threshold for the acoustic reflex. Results indicate that, while individual components of the total impedance battery lack diagnostic precision, the overall pattern of results yielded by the complete battery can be of great diagnostic value, especially in the evaluation of young children.

https://jamanetwork.com/HttpHandlers/ArticlePdfHandler.ashx?journal=OTOL&articleId=603185&pdfFileName=archotol_92_4_002.pdf

Clinical experience with impedance audiometry.

In mammals, environmental sounds stimulate the auditory receptor, the cochlea, via vibrations of the stapes, the innermost of the middle ear ossicles. These vibrations produce displacement waves that travel on the elongated and spirally wound basilar membrane (BM). As they travel, waves grow in amplitude, reaching a maximum and then dying out. The location of maximum BM motion is a function of stimulus frequency, with high-frequency waves being localized to the “base” of the cochlea (near the stapes) and low-frequency waves approaching the “apex” of the cochlea. Thus each cochlear site has a characteristic frequency (CF), to which it responds maximally. BM vibrations produce motion of hair cell stereocilia, which gates stereociliar transduction channels leading to the generation of hair cell receptor potentials and the excitation of afferent auditory nerve fibers. At the base of the cochlea, BM motion exhibits a CF-specific and level-dependent compressive nonlinearity such that responses to low-level, near-CF stimuli are sensitive and sharply frequency-tuned and responses to intense stimuli are insensitive and poorly tuned. The high sensitivity and sharp-frequency tuning, as well as compression and other nonlinearities (two-tone suppression and intermodulation distortion), are highly labile, indicating the presence in normal cochleae of a positive feedback from the organ of Corti, the “cochlear amplifier.” This mechanism involves forces generated by the outer hair cells and controlled, directly or indirectly, by their transduction currents. At the apex of the cochlea, nonlinearities appear to be less prominent than at the base, perhaps implying that the cochlear amplifier plays a lesser role in determining apical mechanical responses to sound. Whether at the base or the apex, the properties of BM vibration adequately account for most frequency-specific properties of the responses to sound of auditory nerve fibers.

/pdf/mechanics-of-the-mammalian-cochlea-368l279klj.pdf

Mechanics of the Mammalian Cochlea

The first edition of this book has enjoyed a gratifying existence. 1s sued in 1965, it found its intended place as a research reference and as a graduate-Ievel text. Research laboratories and universities reported broad use. Published reviews-some twenty-five in number-were universally kind. Subsequently the book was translated and published in Russian (Svyaz; Moscow, 1968) and Spanish (Gredos, S.A.; Madrid, 1972). Copies of the first edition have been exhausted for several years, but demand for the material continues. At the behest of the publisher, and with the encouragement of numerous colleagues, a second edition was begun in 1970. The aim was to retain the original format, but to expand the content, especially in the areas of digital communications and com puter techniques for speech signal processing. As before, the intended audience is the graduate-Ievel engineer and physicist, but the psycho physicist, phonetician, speech scientist and linguist should find material of interest."

Speech Analysis, Synthesis and Perception

Phantom auditory perception (tinnitus): mechanisms of generation and perception

A theory of temporal auditory summation is developed and applied to the threshold of audibility for various temporal patterns of pulses and sinusoidal vibrations. The theory is based on the assumption of an exponential decay of neural excitation and, for the threshold of audibility, it includes only one time constant. Various factors that may affect temporal auditory summation are discussed. It is shown that the same theory applies to muscle contractions.

Theory of Temporal Auditory Summation

The hypothesis that, in magnitude estimation and production, subjects tend to pair numbers with sensation magnitudes on absolute rather than ratio scales is tested experimentally. This implies that not only sensations, but also numbers acquire absolute psychological magnitudes. The specific experiments are performed on loudness and line lengths. The latter reveal that the subjective magnitudes of numbers are formed before the age of 6 and do not change after that age. It is suggested that the absolute coupling of numbers with sensation magnitudes originates from the concept of numerosity where numbers have absolute meanings. This work was supported by N1H Grant NS-03950.

/pdf/absolute-scaling-of-sensory-magnitudes-a-validation-49l3oj8pmd.pdf

Absolute scaling of sensory magnitudes: a validation.

A quantitative theory of the middle‐ear acoustics is developed and expressed in terms of an electric analog. The analog network is based on the functional anatomy of the middle ear. The numerical values of its elements are derived from impedance measurements on normal and pathological ears and from anatomical data. It is shown that the input impedance of the analog agrees within the experimental error with the acoustic impedance at the eardrum, and that changes in analog parameters corresponding to known anatomical changes produce the same effect on its impedance characteristics as measured at the eardrum.

Analysis of the Middle‐Ear Function. Part I: Input Impedance

A quantitative psychophysiological theory is developed for loudness level and loudness as a function of stimulus duration. It is based on the psychophysical as well as neurophysiological evidence that the apparent temporal summation of acoustic energy is a result of neural summation at a high level of the auditory system. The theory shows how this can be achieved in spite of a nonlinear relationship between sound intensity and neural excitation. The temporal decay of neural firing preceding the final stage of temporal summation seems to be responsible for overcoming the nonlinearity.

Temporal Summation of Loudness: An Analysis

A monaural loudness function is determined for 1000 cps and compared to a previously obtained binaural loudness function. Although the monaural function appears to have a somewhat smaller exponent than the binaural one, the empirical evidence does not permit rejection of the hypothesis of a simple interaural loudness summation. The psychophysical methods of magnitude estimation with and without a designated standard and of magnitude production without standards are used. A combination of magnitude estimation and production without standards is accepted as a method with minimum bias and classified under a more general methodological category called “psychological magnitude balance.”

Jozef J. Zwislocki

Papers

Theory of Temporal Auditory Summation

Absolute scaling of sensory magnitudes: a validation.

Analysis of the Middle‐Ear Function. Part I: Input Impedance

Temporal Summation of Loudness: An Analysis

Monaural Loudness Function at 1000 cps and Interaural Summation