The sense of pitch and local increase in threshold

Abstract

The pitch of a pure tone depends basically on its frequency, but it can sometimes be modified by the intensity of the tone. Hitherto, in work on the modifying influence of intensity (e.g. Stevens, 1935;Snow, 1936;Morgan, Garner & Galambos, 1951) the subjects have been chosen for their normality of hearing. It is reported by Morgan et al. (1951) that it is typical for such subjects to find pitch almost independent of intensity. In the present work, the effect of intensity on pitch for subjects with slight hearing defects has been examined.The intensity-dependence of pitch has been studied as a function of the magnitude ofthe hearing defect. This introduces a variable which is independent of any experiments on normal ears. APPARATUS AND TECHNIQUE Apparatu8For the air-conduction audiogram, an Amplivox model 61 audiometer was used.A block diagram of the apparatus used for the main series of tests is shown in Fig. 1. Two beat-frequency oscillators were used, B.S.R. type L.O. 50A, slightly modified to reduce noise. The output transformers were matched to a low impedance line. The frequency control of oscillator 2 was connected to the rotary condenser by a reduction gear, so that a pointer attached to the control spindle magnified the motion of the frequency dial by a factor of five. The pointer moved against one of a set of frequency scales, each calibrated for use with a particular frequency of the standard tone. The marks on the scale were numbered from 1 to 10 at equal frequency intervals, and the standard frequency was represented by a mark at the middle of the frequency range. The frequency intervals between the graduation marks were 100, 200 and 500 c/s, on different scales, the size of interval used in a particular test depending on the subject's ability to discriminate pitch.One moving-coil earphone was used, S.T. and C. type 4026A, and a dummy earphone excluded noise from the opposite ear. The earphones were supported by a spring headband, and were provided with sponge-rubber rings to ensure that they fitted closely on the ears.The attenuators were made by the author, to match the low impedance of the headphone. Each was variable in steps of 5 db, and gave up to 130 db of attenuation.

Comparison of Place-versus-Pitch Mismatch between a Perimodiolar and Lateral Wall Cochlear Implant Electrode Array in Patients with Single-Sided Deafness and a Cochlear Implant

“…Consequently, in our current results, the pitch matches may have been influenced by (mainly highfrequency) hearing loss in the better ear. However, we know that the influence of loudness on pitch perception is negligible in the tested range (50-65 dB HL) [Strange, 1955]. Second, there was a small sample size (CI422 group: n = 8, CI512 group: n = 6).…”

“…The manually presented acoustic stimuli had a minimum duration of 500 ms. For the first run of measurements per electrode, we adjusted the level of a 1-kHz acoustic tone (median 60 dB HL, range 50-65 dB HL) to match it to the loudness of the electric stimulus in the CI ear (C-level of the most frequently used program). In this range (50-65 dB HL), the influence of loudness on pitch perception is negligible [Strange, 1955]. The task was to compare the pitch of two acoustic stimuli to the pitch of the electric stimulus and select the acoustic stimulus with greatest similarity in pitch.…”

Pitch‐intensity dependence and its relation to the threshold of hearing for high frequencies

“…These results show that at frequencies between 1000 and 8000 c/s it is indeed abnormal for the pitch of a pure tone to be dependent on intensity to any great extent. The author's earlier work (Strange, 1955) suggested very strongly that this was so, both because the magnitude of the pitch changes increased with the hearing loss, and because pitch was almost independent of intensity outside a limited frequency range close to that of the threshold defect. It is now shown that in the absence of such a dip in the audiogram, and of any other obvious threshold defect, the pitch of pure tones is hardly affected by intensity.…”

“…Plotted on a logarithmic diagram of frequency against intensity, a straight line may be fitted to these points, whose slope is a measure of the degree of dependence of pitch on intensity. The details of this calculation are in the previous paper (Strange, 1955). Tests were performed for each subject with the standard frequency 4000 and 6000 c/s.…”

Hearing

“…Strange (158) has reported an experiment in which she studied the effect of intensity on pitch in subjects with a dip between 3000 and 6000 c.p.s. in the audiogram of at least one ear.…”