Paul Milner

Speaking rate of adventitiously deaf male cochlear implant candidates

No objective group data on speaking rate or speaking duration have been reported on the speech of adventitiously profoundly hearing-impaired adults. Results of the present study showed that speaking rate, i.e., number of syllables per second, was significantly slower and speaking duration was significantly longer for 25 adventitiously profoundly hearing-impaired adult male cochlear implant candidates than for 10 normal-hearing control subjects. The factors of length of time since onset of profound hearing loss and hearing aid use did not significantly affect speaking rate. Based on these objective data, a rationale and method are presented for aural rehabilitation of the profoundly hearing-impaired who exhibit speaking rate abnormalities.

Voice intensity of prospective cochlear implant candidates and normal hearing adult males

Voice intensity in 19 prospective cochlear implant candidates, all adventitiously profoundly sensorineurally deaf adult males, was investigated. For the first time with objective data, it was shown that such deaf subjects spoke with significantly increased voice intensity and with greater intensity fluctuations than normal hearing male speakers. Neither length of time of profound deafness nor history of hearing aid use significantly affected voice intensity. Based on quantitative data, rehabilitation of voice intensity problems in the adventitiously deaf is indicated.

Standardization of four videotaped tests of speechreading ranging in task difficulty.

Repeated measures are needed to assess speechreading ability of prospective cochlear implant candidates and to follow their progress over the course of treatment. To perform such measures, high quality color videotaped versions of four speechreading tests were constructed using a male and a female speaker. Materials were selected to provide gradations in task difficulty ranging from responses to questions with the topic known, to verbatim repetition, to abstraction of information from a spoken paragraph in order to answer questions. The tests were: (1) NAL/West Haven modification; (2) Iowa-Keaster, Forms A and B; (3) CID Everyday Sentences; and (4) Gold Rush Paragraph. The tapes were standardized by presentation to young adult normal subjects. Results indicated that a range of performance could be measured by using the present tests as a battery, although the anticipated ranking of tests was not obtained.

Perception of filtered speech by hearing‐impaired listeners and by normal‐hearing listeners with simulated hearing loss

Six subjects have participated in a study to determine the relationship between actual and predicted performance‐intensity functions for nine conditions of high‐pass, low‐pass, and band‐pass filtered speech. Three subjects have bilateral sensorineural hearing loss of varying degrees and etiology, one subject has a unilateral sensorineural loss and two subjects have normal hearing. All subjects were trained and tested on 72 consonant‐vowel syllables recorded by two male and two female talkers. Each of the nine filtered conditions (as well as the unfiltered speech) was tested at a minimum of five different levels. Hearing loss in the normal‐hearing subjects was simulated by using spectrally shaped wide‐band noise to create masked thresholds similar to those of the hearing‐impaired subjects. Measured intelligibility scores are compared with the predictions of Articulation Theory using modifications developed by Dugal, Braida, and Durlach [in Acoustical Factors Affecting Hearing Aid Performance and Measurement, edited by Studebaker and Hochberg, (1980)] [Research supported by NIH.]

Intelligibility of voice transmission through a satellite relay system

An extensive series of measurements of speech intelligibility of voice modems designed for a satellite relay link to air and sea‐going craft has been underway since 1973. Measurement parameters for these tests are the system functions associated with ATS‐6 satellite L‐band and C‐band transmission. These include comparative evaluations of intelligibility versus C/N0, angle of elevation, antenna systems, range, and sea‐state. For these tests, a number of modifications and adaptations of standard intelligibility testing procedures were developed. These include using a large number of scramblings of the PB‐50 word lists (ANSI S3.2‐1960) recorded by four professional talkers, two male and two female, in an anechoic room. Because of time considerations in conducting the flight tests, the lists were recorded at a reading rate of 2.5 sec with no carrier phrase Experiments showed that highly trained listeners [P. Milner, “Advantages of Experienced Listeners in Intelligibility Testing,” IEEE Trans. Audio Electroaco...

Transitivity of Loudness Level

In mathematics, the law of transitivity states quite simply that if A = B and if B = C, then A =C. The question of whether the law of transitivity holds for loudness level was investigated in this study to confirm an observation made in a previous report without adequate proof. [B. B. Bauer and E. L. Torick, “Researches in Loudness Measurement,” IEEE Trans. Audio Electroacoust. AU‐14, No. 3, 141–151. A panel of eight women were presented octave bands of pink noise from 125 Hz to 250 Hz to 2 kHz to 4 kHz, known to be at 70 phons loudness level, referred to a 13‐oct band of pink noise centered at 1 kHz. They were asked to compare the loudness of any octave band to each of the other bands also at 70 phons until all were compared. The stimuli were presented through a loudspeaker in a listening room with known acoustical properties. The results indicate that loudness level is indeed transitive. An analysis of variance is performed on the data to support the findings.

Application of articulation theory to the study of speech reception by the hearing impaired

Roughly 40 years have elapsed since articulation theory was applied to the analysis of speech reception measurements on impaired listeners made in conjunction with the “Harvard” and MEDRESCO hearing aid studies. We review three recent applications of articulation theory for similar purposes. In one study, it was used to predict the effect of varying the frequency‐gain characteristic of amplification systems used by listeners with sharply sloping high‐frequency losses. In a second study, it was used to evaluate the results of high‐, low‐ and bandpass filtering applied to speech for five listeners with flat and sloping losses. In a third study, it was used to predict speech reception in noise for hearing‐impaired listeners with a variety of audiograms. The successes and limitations encountered in these applications, and possible modifications of the theory, will be discussed. [Work supported by NIH.]

Speech reception in deaf adults using vibrotactile aids or coehlear implants

Many post‐lingually deafened adults rely heavily upon speechreading as the primary source of speech information. Vibrotactile aids or cochlear implants may help augment the limited visual cues of speeehreading, especially the ones which permit voiced/voiceless and nasality distinctions. Measures of the apprehension of voicing and nasality, as well as other attributes of speech reception, were obtained using the Diagnostic Rhyme Test [W. D. Voiers, in Benchmark Papers in Acoustics, Vol. 11, edited by M. Hawley, pp. 374–387 (1977)] with candidates for possible cochlear implantation. Results using vibrotactile aids or cochlear implants either individually or in combination with speechreading indicated that both vibrotactile aids and cochlear implants provided improvements in the perception of nasality, but voiced/voiceless distinctions were not as clearly recognized. [Work supported by Veterans Administration Rehabilitation Research and Development Service.]

Learning/adjustment effects in intelligibility testing

A PB50 test procedure especially formatted for time saving (without carrier sentence) was used in 1974/75 to measure the intelligibility quotient of Satellite Communications Modems. Tests performed within 1–2, 3–4, and 5–6 months after the start of program were repeated by the same team in 1977. Interesting learning/adjustment effects were observed. It appears that the utilization of an unfamiliar PB50 speaker/procedure test sequence may require a 24‐session‐hours learning period before stability is achieved. [This program was supported in part by the U.S. Department of Transportation.]

Subjective sound quality of all‐pass networks

In an earlier study [J. Acoust. Soc. Am. 54, 334 (1973)] we reported that the subjective quality of music appeared to be unaffected by processing signals through all‐pass phase‐shift networks as used in the SQ quadraphonic matrix encoding system. These conclusions were based on the results of a same/different experiment in which the listeners appeared to be operating at a chance level for a two‐alternative forced‐choice paradigm. They responded with an equal likelihood (50%) of same and different regardless of the nature of the stimulus pairs. Additional experiments have been performed with speech samples using several lists of Harvard PB Sentences. In a same/different experiment, the listeners overwhelmingly judged “same” regardless of conditions. However, in an A‐B‐X experiment, the listeners favored the “B” choice, the one nearest the time to the unknown. Foil conditions of high‐pass filtering, low‐pass filtering, and peak‐clipping were included to verify the performance of the listeners. Correct respo...