bluuebunny/crossref_metadata_2025 huggingface dataset:
Responses of auditory-nerve fibers to consonant—vowel syllables
Authors: Sinex Donald G. , Geisler C. Daniel
Published: October 2005

Discharge patterns of cat auditory-nerve fibers were elicited with a series of synthesized speech sounds as stimuli. The sounds differed in the starting frequencies of formants two (F2) and three (F3), or in the duration of the transition. Fibers with characteristic frequencies (CF's) less than 800 Hz respond primarily to components near the first formant (F1), or, for the lowest CF's, to the fundamental frequency (F0). The responses of fibers with higher CF's may include several prominent components. For CF's between 800–1600 Hz, the response is usually dominated by a component near F2 at low intensity, but as F2 changes or intensity increases, F1 may dominate. If the frequency of F3 is low, F3 may also dominate: as F3 rises, the dominant component abruptly switches to F2. For CF above 1600 Hz, all formants may be represented in the response. Again, increases in intensity or changes in the instantaneous frequencies of the formants may alter the relative contributions of response components. [Supported by NIH.]
Spontaneous nasalization
Authors: Ohala John I. , Amador Mariscela
Published: October 2005

Distinctively nasal vowels usually develop from earlier sequences of vowel + nasal consonant. There are exceptions, however, called instances of “spontaneous nasalization,” where an earlier nasal is lacking, e.g., Hindi [sɑ̃:p] “snake” from Sanskrit sarpa; English [hɑ̃vəd] “Harvard.” Curiously, most such spontaneously nasalized vowels have obstruents with high airflow next to them, e.g., voiceless fricatives. We tested a hypothesis that vowels flanking such consonants might sound nasalized without being nasilized if produced with a slightly open glottis via assimilation to the greater-than-normal glottal opening required by the high airflow segments. The spectral effects of open glottis duplicate those of nasilization: increased formant bandwidth, etc. Physiological recordings of syllables such as [bis], [bɑs], by two speakers each of American English and Mexican Spanish showed no true nasalization on the vowels but did show appreciable glottal opening just before the [s]. Using digital techniques, the last complete period of these vowels before the [s] was iterated into a steady-state vowel 400 ms long and presented to listeners who, as predicted, judged them to sound significantly more “nasalized” than control stimuli. [Supported by NSF.]
Velar coarticulation in nasal and oral vowel environments: A comparison of English and Hindi
Authors: Bell-Berti Fredericka , Henderson Janette B. , Honda Kiyoshi
Published: October 2005

Velar elevation in English is greater for close than for open vowels and is also affected by adjacent consonants. Vowel quality also affects velar position during consonants, the velum being lower in an open- than in a close-vowel environment. In the present study, data on the effects of vowel quality and consonantal environment on velar elevation were collected for Hindi, a language in which the oral-nasal contrast is phonologically relevant for both vowels and consonants, and for English, in which the oral-nasal contrast for vowels is generally considered irrelevant. Simultaneous high-speed films of velar position and electromyographic signals from the levator palatini muscle were collected for a series of vowels varying from close to open in four consonantal environments. The results will be discussed in relation to a velar function model requiring at least four positional states. [Bell-Berti, in Speech Communication Papers, edited by J. J. Wolf and D. H. Klatt (New York, 1979), pages 79–82.] [Work supported by NINCDS.]
Imitation of speech segment duration: Intersegment influences
Authors: Karno Eileen , Porter R. J.
Published: October 2005

How do perception and production share responsibility for speech segment duration? We've reported that listeners imitate 100–400 ms-duration /s/-segments in /asV/ syllables with an accuracy paralleling that seen for nonimitation, nonspeech, duration-discrimination. The speech motor system's ability to control duration can, then, match the perceptual system's sensitivity to duration. This is apparently not always the case, however, since the constant-duration, 400 ms, initial /a/ of the /asV/ syllables was not accurately imitated: The /a/ tended to be produced shorter (longer) when followed by a shorter- (longer-) /s/. Perhaps the speech motor system's ability to control durations of successive segments is constrained in that durations “targeted” for later segments might be “anticipated” during the production of earlier segments. The present study investigated this possibility by asking listeners to imitate /asu/ syllables in which both the /s/ and the /a/ varied in duration. Results confirmed our expectation: The backward influence of /s/ duration on /a/ duration was greater than the forward influence of /a/ on /s/. A follow-up perceptual-judgement study suggested that, in addition to possible motor effects, /s/ duration may sometimes influence the perceived duration of the /a/. (Laboratory facilities provided, in part, by the Kresge Foundation.)
A syllabic component of speech motor control?
Authors: Song C. S. , Perkell J. S.
Published: October 2005

Some recent experimental results appear to contradict the usual finding that anticipatory coarticulation crosses syllable boundaries. For example, averaged EMG records of the posterior genioglossus during /ipi/ and the orbicularis oris during /utu/ have shown a peak of activity for each vowel with a diminution or “trough” corresponding to the consonant. These and other findings have been interpreted as support for a syllable-based component of speech motor control [cf., T. Gay, J. Acoust. Soc. Am. 62, 183–193 (1977); T. Gay in Segments and Syllables, edited by A. Bell and J. Hooper (North Holland, Amsterdam, 1978)]; however, other factors may be implicated. Measurements of lower lip protrusion for nonsense utterances containing the sequence /kuCnu/ (n = 1−3) were made on speakers of American English, French and Spanish. Movement records show considerable variation, including examples of trajectories with and without troughs. Quantitative analysis of trough depth as a percentage of the displacement for the entire rounding gesture suggests several possible sources of variation: Language, individual, consonant type, and cluster duration. Thus it seems premature to attribute the existence of troughs to any single factor. [Research supported by NIH Grant No. NS04332.]
Diphthongal types and their underlying articulatory strategies
Authors: Collier Rene , Bell-Berti Fredericka , Raphael Lawrence J.
Published: October 2005

In many languages both glides and vowels are found in tauto-syllabic sequences preceding vowels. The phonological interpretations of these sequences may differ from one language to another. In English, for instance, glide + vowel is usually considered a CV sequence; while vowel + vowel is interpreted as a V (diphthong). In contrast, Dutch interprets both types of phonetic sequences as phonologically contrastive diphthongs, although of differing articulatory types. Acoustic and electromyographic analyses of the utterances of a native speaker of Dutch indicate that the two types of Dutch diphthongs are distinguished both by the nature and the number of the articulatory gestures which produce them. The differences between the diphthongs suggest an analysis into unitary versus sequential segmental types. [Work supported by NINCDS.]
Is a stop consonant released when followed by another stop consonant?
Authors: Henderson Janette B. , Repp Bruno H.
Published: October 2005

Phoneticians have generally claimed that, in sequences of two-stop consonants in English, the first stop is often unreleased. To examine this claim, we recorded sentences, produced by several native speakers of American English at a conversational rate, containing disyllabic words with one of the 24 possible sequences of two nonhomorganic stops across the syllable boundary (e.g., cactus, pigpen). In addition, several sentences containing words with two stops in final position were recorded (e.g., act, sobbed). Oscillograms of the critical words revealed that releases of the first stop were nearly always present, except in those instances where the second stop was bilabial. This is a reasonable result when one considers the articulatory maneuvers involved. Since many of the releases we observed were acoustically rather weak, they may be difficult to detect by ear and thus may escape even the careful listener's attention. [Work supported by NICHD and BRS.]
Effects of linguistic boundary and stress placement on speech dynamics: a preliminary study using a new method to compare articulator movement across utterances
Authors: Liberman Mark Y. , Fujimura Osamu , Kruskal Joseph
Published: October 2005

In order to examine the effects of linguistic boundaries and stress patterns on articulator movement, we have employed a novel method of comparing articulator movement from different utterances. Specifically, we used dynamic programming (“dynamic time warping”) to match the time functions of articulator position provided by the University of Tokyo microbeam x-ray system. Spectral distances were used as the basis for similar time-warping in the acoustic domain. We are thus able to investigate speech timing, as a continuous dynamic pattern, rather than as a sequence of discrete intervals between acoustic or articulatory events, and (in some cases) to consider different articulatory dimensions separately.
Acoustical activities in Western Germany
Authors: Kurtze G.
Published: October 2005

The early history of acoustics in Germany is almost completely laid down in the “Akustische Zeitschrift,” a periodical which existed between 1936 and 1944. It was edited by Martin Grutzmacher and Erwin Meyer, the latter then head of the Heinrich-Hertz Institut in Berlin. In 1947, released from British custody, Erwin Meyer came to Göttingen and became the father of modern German acoustics; he took up a research contract with DSIR (Department of Scientific and Industrial Research) London in 1948 that put him in a position to build up a large institute with activities in all fields of acoustics. Acousticians who graduated from this institute today lead 34 of all important acoustical research institutes in Germany. In 1951 “Akustische Zeitschrift” was succeeded by “Acustica,” a European journal, again with Erwin Meyer as one of the founders and editors. His research contract and the post-war situation in Germany determined the preferred fields of German acoustical research, namely building acoustics, structure-borne sound, room acoustics, and physical acoustics. Scientists working in these fields discussed their problems in the acoustics group of the DPG (Deutsche Physikalische Gesellschaft). Electroacoustics was represented in parallel by the acoustics group of the NTG (Nachrichtentechnische Gesellschaft). With increasing importance of noise control in connection with environmental problems, the VDI (Verein Deutscher Ingenieure) also appeared on the scene, producing technical guide lines and arranging acoustical seminars for engineers. Finally, these three groups in 1969 founded DAGA (Deutsche Arbeitsgemeinschaft für Akustik), an organization now responsible for regular common meetings in all fields of acoustics in Germany, as well as for the representation of German acoustics abroad.
Lecture demonstrations of molecular models of sound
Authors: Wohl Ronald A. , Green David M. , Jones R. Victor
Published: October 2005

Small polyfoam spheres levitated on an upward stream of air provide an effective means for visualizing and studying microscopic models of fluids. Agitated by the air stream and randomized by collisions, the motion of the spheres may be likened to the chaotic motion of the molecules of a gas. “Polyfoam gas” is a striking illustration of many aspects of kinetic theory, but it is particularly useful in the study of sound. One may easily observe the coherent density variations of an acoustic excitation propagating through the randomly moving spheres. Inexpensive apparatus has been developed which makes use of simple household fans and air stream “straighteners.” In this talk we will describe the construction of the apparatus, discuss the properties of polyfoam gas, and present video tapes of lecture demonstrations—e.g., sound pulse propagation, standing waves, diffraction, etc. [These demonstrations were developed as part of a new undergraduate Core Curriculum course in psychophysics.]
A survey of sound insulation between dwellings in the U.K.
Authors: Utley W. A. , Sewell E. C.
Published: October 2005

Field measurements of the sound insulation of over 1200 party walls and nearly 500 party floors have been made in dwellings built in the early 1970s. More than half the walls and over 60% of the floors were found to have a sound insulation performance below that specified as a deemed-to-satisfy requirement in the U.K. Building Regulations. A significant proportion of walls and floors had a very poor performance. In some cases this poor performance could be attributed to particular features in the design and construction of the dwelling. However even when results severely affected by such features are excluded there remains considerable variability between different examples of similar constructions. While it is possible to suggest reasons for this variability, it is not possible at present to account for the variability in a quantitative manner.
Noise-insulation requirements for multi-family dwellings
Authors: Van Houten John J.
Published: October 2005

Noise insulation standards are part of the California Administrative Code (Title 25, Section 1092). These standards apply to all new multi-family dwelling units such as hotels, apartments, duplexes, townhouses, and condominium units. Detached single-family dwellings are specifically excluded. The standards establish minimum requirements for the isolation of interior spaces from exterior noise and set minimum ratings for noise insulation of partitions between dwelling units. A community noise equivalent level (CNEL) of 45 dB is set as the maximum for intrusive noise from exterior sources such as rail or road traffic, or aircraft operations. American Society for Testing and Materials (ASTM) testing procedures for party wall and floor/ceiling system sound transmission provide the basis for setting minimum acceptable performance for separations between units. As a consultant to builders, planners, and architects, the site planning and design of residential projects have been examined and field evaluations have been performed on completed projects. Building designs and the selection of suitable building elements (wall construction composites, window assemblies, vent configurations, etc.) which assure compliance with the standards have been identified. The paper provides a brief description of the standards, their enforcement pitfalls, and an assessment of their impact on residential construction in California.
Improving the effectiveness of sound isolation building codes and regulations
Authors: Lawrence Anita
Published: October 2005

Building codes and regulations designed to ensure sound isolation in multifamily dwellings are frequently inadequate. There are several reasons for this: Firstly, the code may not take account of all relevant acoustic parameters, e.g., reverberation control or the relation between required isolation and external ambient sound; secondly, if the code is written in terms of “deemed to satisfy” constructions it is difficult to ensure that sufficient, technically competent supervision will be provided, and, in addition, details of the joints and junctions between different elements do not normally form part of the code; thirdly, if the code specifies acoustic performance it is difficult and expensive to carry out accurate compliance tests. Increased involvement of competent acousticians in code writing and at all stages of building design and construction appears to be necessary.
Measurements and models of cat middle-ear mechanics
Authors: Lynch Thomas J. , Peake William T.
Published: October 2005

Network models of the middle ear often consist of three sub-networks that represent, respectively, (1) the middle-ear cavities as a one-port network, (2) the tympanic membrane and ossicular chain as a two-port network, and (3) the inner ear as a one-port network. Measurements of the acoustic admittance at the tympanic membrane, Yd, and of sound pressure in both the tympanic and the bullar cavities in the cat have been made (over a frequency range of 10 Hz to 22 kHz) with and without experimental modifications of the cavities. Some of the results were used to define a network model of the cavities. This model predicts independent results quite precisely for frequencies below 8 kHz. Element values for this model of the cavities can be related to anatomical measurements. Measurements of Yd (with the cavities opened) after interruption, fixation, and mass loading of the ossicular chain help constrain a model for the tympanic membrane and ossicular chain. Measurements of the input impedance of the inner ear [Lynch et al. J. Acoust. Soc. Am. Suppl 1 59, S30, (1976)] have also been represented by a network. Predictions of the complete middle-ear model will be compared to independent measurements. [Work supported by NIH and the Whitaker Health Sciences Fund.]
Network concepts and energy flow in the human middle-ear
Authors: Shaw E. A. G. , Stinson M. R.
Published: October 2005

The primary function of the middle-ear is the transmission of sound energy from the earcanal to the cochlea. It follows that the energy flow through the system and energy loss within it are major considerations in middle-ear modeling. These considerations are paramount at high frequencies where the fraction of energy transmitted is small (roughly 2% for the human ear at 10 kHz) and the role of the eardrum is crucial. A review of the evidence bearing on this role leads to an updating of the acoustical network for the human middle-ear advanced in 1977 (J. Acoust. Soc. Am. Suppl. 1 62, S12) and a more refined estimate of the middle-ear transmission curve. This work takes into account recent measurements of earcanal pressure ratio, values of eardrum velocity ratio for the compound eardrum derived from holographic data, and a revised estimate of eardrum dimensions.
Acoustic transmissions through a mesoscale eddy with random currents
Authors: Newhall B. K. , Jacobson M. J. , Siegmann W. L.
Published: October 2005

Acoustic effects due to current perturbations from an idealized cylindrical cyclonic mesoscale eddy are analyzed. Random current fluctuations are required to satisfy conservation of mass, and include random variations in both streamlines and current magnitude. Short-range cw acoustic transmissions through the perturbed eddy are considered, and an approximate solution of the ray equations is found. An approximation for ray travel times is developed in terms of the horizontally averaged source-receiver component of current, and travel-time statistics are investigated. Travel times over different ray paths are found to be nearly perfectly correlated, implying that current perturbations can have significant effects on total-field phase, but have little effect on total-field intensity. Statistics of the horizontally averaged current component are analyzed, and their effects on acoustic phase are determined for various source and receiver locations in the eddy. Current effects on both the mean and the standard deviation of phase are highly dependent on source-receiver orientation and location. [Work supported by ONR.]
Oboe normal mode adjustment via reed-staple proportioning
Authors: Richards W. B. , Benade A. H.
Published: October 2005

We have analyzed a model oboe consisting of a body cone of variable length and fixed truncation (of length x0) at the apical end. The missing apical cone is replaced. by a reed and staple model consisting of a tapered neck and a cylindrical cavity. Computer experiments searched for cavity and neck proportions giving an input admittance (seen at the junction with the main body) closely the same as that of the missing apical cone. It has already been shown that two major constraints on the cavity and neck proportions exist: Their total volume must match that of the missing cone, and their first mode frequency must equal that of the apical segment (fr2 = c/2x0). Subject to these constraints, cavity and neck lengths, diameters, and tapers can be found that make the first four modal frequency ratios harmonic within 5¢ as the length of the body is varied to sweep the first mode over its usual one-octave range. Insight from this work plus study of the effects of small departures from these proportions provides practical guidance for the adjustments of reeds for real oboes, whose air columns are not quite conical in their acoustical behavior. [Work supported by NSF.]
Federal noise research in health effects: 1978–1980
Authors: Shampan Jack , Marrazzo Rudolph
Published: October 2005

This paper will describe the scope of the federally funded research effort between fiscal years 1978–1980 on the effects of noise on the public health and welfare based upon our receipt of over 200 research project abstracts provided by more than 20 federal agencies. General research funding trends have been identified and emerging avenues of research can be seen. The diverse research interests of each agency will be discussed. Overall research funding has increased only 17 percent from a three-year average of $5.8 million in the 1975–77 period to $6.8 million in the 1978–80 period. Steady growth is seen in the research funding levels for agencies such as DOD, NIOSH, NIEHS, EPA and BOM, whereas, other agencies including NASA, NBS, NINCDS, and DOT report declining funding levels. Noise-Induced Hearing Loss remains the single largest research category for federal funding support. DOD, NINCDS, and NIOSH are the major sponsoring agencies of this research. The largest increases in research funding is seen in the research category of Individual and Community Response with NASA, EPA, and DOE as the leading sponsors, and the category of Noise Environment Determination, with DOD and MSHA as the principle sponsors of related research. Although the Second Federal Interagency Research Panel in 1978 recommended that the category of Nonauditory Physiologic Effects receive the largest increase in funding support, actual funding levels have increased by less than 50 percent, due mainly to research support by EPA. This paper will also discuss progress being made to meet other Panel recommendations. Increased knowledge of ongoing and planned research will promote better overall research planning and research coordination by federal agencies and the scientific community. Also towards this objective, EPA has recently developed a Health Effects Research Plan which presents an operational research program for meeting priority research objectives over the next five years.
Measurement and analysis of rail car coupling noise
Authors: Simpson Myles A.
Published: October 2005

The coupling of rail cars during routine railroad yard classification operations is often a major source of noise impact in neighboring communities. To better understand the factors which influence community noise levels, measurements were obtained during a series of 34 controlled car-coupling tests. Each test consisted of a single test car coupling with a string of one or more buffer cars of various types and weights; the rail car speed at impact ranged from 2 to 8 mph. The tests showed that the maximum A-weighted noise level (either fast or slow) of each car-coupling event varied with 30 times the logarithm of the coupling speed. At a given speed, however, the maximum variation due to other factors (car type, weight, configuration) was fairly small (5 to 7 dB). [Work supported by EPA.]
Autonymy, cohort, and logogen models of lexical access: When and how does interactive processing occur?
Authors: Walker E. C. T.
Published: October 2005

The stages of “autonymy” models of lexical processing accept as input the output of a prior stage and operate without active constraint from other stages of processing or sources of knowledge. Outputs from different stages may be compared by a general purpose processor in making response decisions, but processing interactions among stages are prohibited. By contrast, different types of processing proceed in parallel in “interactive” models, with current results from different processes contraining one another. In “cohort” models words are individual active processors which operate on full or partial output from all types of processing. In “logogen” models recognition occurs passively when a threshold level of activation has been reached; these thresholds being raised or lowered by results from a variety of processes. Thus, the argument turns not on whether, but on how and when interaction occurs. There is some evidence that ambiguity and frequency effects persist in the face of constraining contexts, but results from a variety of on-line experiments indicate that the interaction takes place very early in the process of word identification and not exclusively in the process of making response decisions following identification. This evidence also supports the view that interaction occurs in active recognition processes having access to multiple sources of information.
Some simple formulae for normal mode wavenumbers, cutoff frequencies, and the number of modes trapped by a sound channel
Authors: Ellis Dale D.
Published: October 2005

To a good first approximation acoustic propagation in a sound channel is dominated by a finite number of trapped modes. However, exact solutions are known for only a few special cases, making it necessary in general to use numerical methods to solve the normal mode equation. But often one is interested only in the gross features, such as the number of modes or cutoff frequencies, and one does not need the detail provided by a complete normal mode calculation. Even if a normal mode calculation is desired, the computation time can be reduced considerably if the mode numbers can be estimated in advance. In such a case, the WKB method can be used to obtain formulae which, although they are approximate, are given in closed form. In this paper formulae based in exact and WKB solutions are presented for the number of models trapped in some simple sound channels and for the wavenumbers and cutoff frequencies associated with these modes. The number of trapped modes is shown to depend on the gross features of the sound channel, while the distribution of modal wavenumbers depends to a greater degree on the details of the profile shape.
Mechanical mobility methods for ranking structural transmission path strengths
Authors: Douglas B. E. , Smith J. E.
Published: October 2005

This paper examines the utility of mechanical mobility methods for ranking the vibration transmission path strengths in complex fluid-structure radiation problems. Such path-strength determinations are an important factor for selecting appropriate noise control measures and in minimizing the economic impact of corrective action. Emphasis is placed on the direct equivalent force-moment method which is based on the identification of multiple source inputs (i.e., level, location, and degree of freedom), and the characterization of radiating surfaces (i.e., level, location, degree of freedom, type, and coherence with other outputs). This method is shown to serve as a means of experimentally verifying finite element models and as an aid in modeling source-forcing functions.
Assessing the quality of measured mobility data
Authors: Ewins D. J. , Griffin J.
Published: October 2005

A survey has recently been completed in the UK and in France to assess the state-of-the-art in mobility measurement techniques. Specially-designed test structures were circulated amongst some 30 laboratories whose measurements of specified mobility parameters and modal analysis results were collected and compared. Various forms of presentation of the collected data were explored in order to highlight the trends and the areas of both good and poor agreement. The data were also subjected to various statistical analyses in attempts to quantify the scatter. Results from the survey indicated a significant spread of results in most cases. A review is made of the different measurement and analysis techniques used and their influence on the accuracy of the results. [Work sponsored by Ministry of Defence (P.E.).]
Some practical uses of mobility measurements
Authors: DeJong R. G.
Published: October 2005

The availability of digital processing equipment makes it possible to collect a large number of impedance and mobility spectra when studying the vibration characteristics of structures. But are they worth more than the paper on which they are plotted? Some examples are given of ways to use mobility measurements to improve system modeling and determine transmission coefficients in connected structures.
Impedance measurements of joints in mechanical systems with clearances
Authors: Perreira N. Duke
Published: October 2005

Although the motion of mechanical system elements is partially controlled by kinematic constraints, variation in the system motions occur because of the clearances and compliances found in the connections [S. Dubowsky, J. Maatuk, and N. D. Perreira, J. Eng. Ind. 97B, 635–642 (1975); S. Dubowsky and T. Gardner, J. Eng. Ind. 97B, 652–661 (1975)]. In past studies, attempts have been made to model the motions of the system elements when connection compliances and clearances occurred. [R. Herbert and D.C. McWhannel, ASME Paper 76-Det-36] Experimental evidence has shown that these models have some degree of accuracy [S. Dubowsky and S. Young, J. Eng. Ind. 97B, 1116–1125 (1975)]. In this work the primary attempt is to experimentally determine if the above dynamical models can be used to determine the force-motion dependence of the connection clearance and compliance parameters in linkage systems. It is believed that information gained in this study can be used not only in the construction of system dynamical and acoustic radiation models [N. D. Perreira and S. Dubowsky, J. Acoust. Soc. Am. 67, 557–562 (1980)1, but also in developing mechanical wear models for various system joints. [Work supported by NSF.]
Relationships between ultrasonic biologic effects in the eye and other organs
Authors: Lizzi Frederic L.
Published: October 2005

Over the past years, a concerted effort has been undertaken to elucidate biological effects of high-frequency, focused ultrasound in the eye. These studies were initially motivated by the lack of experimental data at the high frequencies (e.g., 10 MHz) used in ophthalmic diagnosis. More recently, interest has shifted to potential therapeutic roles of intense ultrasound in treatment of such conditions as retinal tears, uncontrolled glaucoma, vitreous membranes, and choroidal tumors. The threshold curves and effective exposures found in these studies bear interesting relationships to theoretical predictions and experimental observations for other organs. Relevant data for several ocular structures and simulated disorders will be presented. These will be compared to results from other laboratories which pertain to lesions in brain, kidney, liver, and testes and to effects in experimental animal tumors. [Work supprted by NIH.]
Production of thymine base damage in ultrasound exposed EMT6 mouse mammary sarcoma cells
Authors: Dooley David A. , Sacks Peter G. , Miller Morton W.
Published: October 2005

Mouse mammary sarcoma cells, line EMT6 Ro, were exposed for 1 min to 1-MHz continuous wave ultrasound over a range of intensities from 0.5 to 30 W/cm2. The presence of thymine base damage products of the 5,6-dihydroxy-dihydrothymine type was determined by an alkali degradation assay. Production of damage was found to be greatest at an intensity of 10 W/cm2 and fell off rapidly above and below this intensity. Cells were also exposed for up to 5 rain at 5 W/cm2. A linear increase in thymine base damage was demonstrated with increasing time of exposure such that the rate of production at 5 min was approximately 4 times greater than that of a 1 min exposure. As a positive control, cells received absorbed doses of 60Co gamma rays up to 930 Gy. The amount of base damage produced at 10 W/cm2 ultrasound was approximately equivalent to a gamma ray absorbed dose of 177 Gy. Assay of cells immediately after sonication at 10 W/cm2 showed that approximately 14% of the cells had lysed. Survival data demonstrated that of the remaining unlysed cell population approximately 5% were viable, whereas cells exposed to 177 By showed no survival.
Structural changes produced by intense ultrasound in the mammalian CNS as viewed by electron microscopy
Authors: Borrelli M. J. , Bailey K. I. , Dunn F.
Published: October 2005

Earlier studies [Science 127, 83 (1958)] showed that functional changes-appear virtually instantaneously in response to appropriate ultrasonic exposure of CNS structures, though structural changes, as observed by optical microscopy, did not become manifest until approximately 10–15 min later [A.M.A. Arch. Neurol. Psychiatry 75, 15 (1956)]. It was thus believed that the ultrasound acted initially upon structures too small to be observed in the light microscope, and that time was required for the physiological progression to proceed to appropriate dimensions for observation [Am..!. Phys. Med. 37, 148 (1958)]. Recent studies [Ultrasound Med. Biol. 5, 167 (1979); 6, 1239 (1980)] have shown that ultra-structural organelles such as mitochondria, nuclei, endoplasmic reticulum, lysosomes, and attached ribosomes are indeed affected by ultrasound. It has now been observed that ultrasound also affects, within very short periods of time, synapses. thus providing an explanation for functional changes observed virtually instantaneously with the ultrasonic insult. Dosage conditions are in the neighborhood of 300 W/cm2 for 1 s at 1 MHz. Changes have also been observed in microtubules, neurofilaments and free ribosomes, in addition to previously unreported morphological alterations in nuclei and mitochondria. [This research was supported by the National Science Foundation.]
Acoustics of the marginal ice zone
Authors: Votaw Charles W.
Published: October 2005

The marginal sea ice zone is defined as the band around the edge of the Arctic in which the presence of sea ice is seasonal. It extends from the line of minimum ice cover which exists in about September to the maximum extent of ice coverage which happens in about April. The special acoustic problems of the area involve a normally upward refracting profile and repeated reflection off the rough underside of the ice. The continuous sunlight of the summer months causes melting and the establishment of surface ducts. The action of wind and wave on the ice edge generates broadband noise characteristic of surf noise. Propagation prediction models and the expected range of environmental input parameters will be presented. Data for this presentation will be drawn primarily from work in the Greenland Sea.
Signal coherence modeling for ice-covered shallow water
Authors: Ozard John M. , Brooke G. H. , Wilmut M. J. , Greening M. V.
Published: October 2005

A normal mode model is used to predict signal coherence for a moving sound source in shallow water. In the model, modal amplitude and phase are assumed to fluctuate. The fluctuations are taken to derive from the effect of ice under-surface roughness and bottom roughness. For conditions under which only a few modes are important, model coherence was calculated for vertically or horizontally separated sensors. At these low frequencies, and with sensors separated by the order of a wavelength, considerable loss of coherence can occur particularly at certain depths. With horizontally separated sensors, the coherence shows a periodicity rather than a monotonic decrease with increasing sensor separation. This periodicity occurs over a few wavelengths.
Effect of signal phase on the detectability of a tone masked by two closely-spaced tones
Authors: Hartmann W. M.
Published: October 2005

We reopen the question of an appropriate representation to describe the masking of a sine tone midway in frequency between two maskers [A. R. Phipps and G. B. Henning, J. Acoust. Soc. Am. 59, 442–447 0976)]. We argue that when the maskers are closely spaced in frequency, signal detection is mediated by recognizable differences in the stimulus envelope. For unit maskers, separated in angular frequency by δ, and for signal amplitude a, the square of the envelope is given by ‖E‖2 = 2 + 2 cos (δt) + a2 + 4a cos φ cos (δt/2), where φ is the signal phase relative to the mean of the masker phase angles. Rhythmic envelope variations caused by the signal occur at a rate of δ/(4π) Hz. Our 2IFC detection experiments find that for sufficiently long signal durations the large dependence on signal phase reported by Phipps and Henning is greatly reduced. [Work supported by NSF grant BNS 79-14155.]
The effects of probe duration on simultaneous-masking tuning curves
Authors: Norton Susan J. , Wier Craig C.
Published: October 2005

Monaural masked thresholds were obtained for tone bursts in a simultaneous-masking paradigm as a function of masker frequency and probe duration. Probe frequency was 1000 Hz and probe durations ranged from 20 to 250 ms. Temporal-integration functions were determined for the probe and it was presented at both fixed SLs SPLs. Masker duration was fixed at 250 ms. Data were collected primarily with a method-of-adjustment procedure. The extreme probe durations were also measured using a two-interval forced-choice procedure. The effects of probe duration in simultaneous-masking paradigms on estimates of frequency selectivity based on tuning-curve parameters will be discussed. [Research supported by PHS Grant No. RR-07096, and grants from NINCDS and the Deafness Research Foundation.]
Estimates of the ratio of external to internal noise obtained using repeatable samples of noise
Authors: Gilkey R. H. , Hanna T. E. , Robinson D. E.
Published: October 2005

Several experiments conducted in our laboratory have used repeatable noise as a masking stimulus. The proportion of trials on which a subject made identical decisions when presented with identical signal-plus-noise or noise-alone stimuli was used to estimate the ratio of external to internal noise standard deviations (R). R was estimated using 2AFC; single interval, Yes-No; and single interval, four-category rating paradigms. The effect of both signal level and noise level on the obtained value of R were systematically investigated. Diotic and dichotic conditions were compared. In discussing these results, the assumptions necessary to estimate R are evaluated. Particular emphasis is placed on considerations of whether the internal noise is independent of the external noise. The forms of the internal and the external noise distributions are also examined. [Work supported by NSF.]
Middle-ear mechanics: Comparison of cat and alligator lizard
Authors: Rosowski John J. , Lynch Thomas J. , Peake William T.
Published: October 2005

Although the middle ears of cat and alligator lizard have similar components [tympanic membrane (TM), middle-ear cavities, and ossicular system], there are clear differences such as the number of ossicles and the structure of the TM. Mechanical responses of these two types of middle ear were investigated with measurements of the input admittance at the TM with the cavities open (Yd). Comparisons are made over the 10 Hz–15 kHz range. For cat Yd is compliancelike below 1 kHz and approximately resistive at higher frequencies. In lizard Yd is also compliance dominated below 1 kHz, and resistive near 2 kHz, but is masslike above 3 kHz. Admittance was also measured with the cochlear load removed and interrupted or fixed ossicular systems. Preliminary conclusions are: (1) In cat and the cochlear load has a large effect on Yd, while in lizard Yd is relatively independent of the cochlea. (2) In the lizard Yd is primarily determined by the TM. (3) The ossicular systems, by themselves, contribute little to Yd in either species. [Work supported by NIH and the Whitaker Health Sciences Fund.]
Admittance of the middle ear system under general anesthesia with nitrous oxide and oxygen in humans
Authors: Normandin N. , Plamondon L. , Perreault L. , Rousseau P. , Blain R. , Girard M. , Forget G.
Published: October 2005

Middle ear susceptance and conductance were measured before, during, and after general surgery on fifteen subjects. Tympanometric pressure increased with diffusion of gases in the middle ear for all subjects and subsequently decrease due to physiological ventilation for 86.7% of the sample as expected [Perreault et al., Can. Anaesth. Soc. J. (March 1981) (in press)]. However, the changes in shape of the tympanograms and values of the resistance, mass, and stiffness were highly variable. The middle ear system was more mobile than the average as evidenced by the frequent occurrence of regular and irregular W patterns. This did not correlate with microscopic eardrum examination but did correlate with hypermobility of the tympanic membrane found in a control group for which admittance was measured only prior and after surgery. Finally, after anesthesia, diffusion of gases from middle ear caused high negative pressure for 30% of the subjects. This result could be predicted from poor active Eustachian tube function tested before anesthesia. [Work supported by Alma Mater.]
Second formants in fricatives
Authors: Soil Sigfrid D.
Published: October 2005

Acoustic analyses of the sibilant fricatives, [s, z, ∫, ȝ], produced in initial position before [a], [i], and [u] were performed. LPC spectra revealed reliable anticipatory vowel coarticulation effects, viz., spectral peaks affiliated with the second formant of the following vowel, present 30–60 ms before vowel onset. These peaks represent oral resonances excited by either aspiration or voicing and indicate that during the latter part of the fricative the constriction begins to open in anticipation of the vowel. Acoustic characteristics of the peaks varied with vowel context due to differences in the anticipatory coarticulation of each vowel. In the context of the high vowels, [i, u], both assimilation and articulatory overlap of the fricative and vowel configurations was evident from the frequencies of the clearly defined spectral peaks. However, in the [a] context the opposing configurations for the fricative constriction and the low back vowel, which are executed sequentially, resulted in poorly differentiated peaks. The data are congruent with perceptual evidence that high vowels are more accurately identified than low vowels in fricatives excised from fricative-vowel syllables, thus exemplifying links between articulatory, acoustic, and perceptual aspects of coarticulation.
Cross-linguistic differences between fricatives
Authors: Nartey Jonas N. A. , Javkin Hector Raul
Published: October 2005

Various cross-linguistic studies indicate that we can safely utilize formant frequency measures in distinguishing English [i], for instance, from French [i]. When it comes to fricatives, there is no reliable cross-linguistic method. This paper presents what we hope to be the dimensions by which fricatives may be described in a meaningful cross-linguistic way. Five to ten speakers each of a number of American Indian, Indo-European, Asian, and African languages produced fricatives in a sentence frame in three-vowel environments; i-i, a-a, u-u. A 50 ms section of each fricative was subjected to a critical-band analysis. The resulting spectra were then compared for fricatives within and between the languages.
A comparison between vocal tract length estimates from acoustic and x-ray data
Authors: Lonchamp F. , Zerling J. P.
Published: October 2005

Thirty vocal tract length measurements from lip corners to glottis were obtained from cine-x-ray sagittal views and lateral-frontal photographic data. Material for two French speakers includes vowels [i, ɛ, ɑ, ɔ, u] in three symmetric [ə CVC] frames where C is either [b, d] or [g]. Four formant frequencies were measured from the simultaneous audio recording using covariance LPC on closed glottis sections, and were corrected for the frequency effects of lip radiation and wall vibrations. Calculated bandwidths from Fant's data and the modified formant frequencies were used to derive area functions for several tract lengths. Use of Paige and Zue's criterion [IEEE-AU 18, 268–270 (1970)] of minimum perturbation with respect to a uniform tube yielded close agreement between measured and estimated lengths for all vowels except [u]. Removal of the last (lip) section in criterion calculations gives better results for [u].
Estimation of the intrinsic duration of vowels
Authors: Nishinuma Y. , Barber S. , Hirst D. J.
Published: October 2005

With the intent of formulating a simple method to estimate the intrinsic duration of vowels, we examined three groups of experimental data and twelve groups of published data from various works concerning six languages. By adopting a linear model hypothesis, we carried out a multiple linear regression analysis, using measured vowel duration as the dependent variable, and its corresponding F1, F2, F3 and a computed variable Dq representing sub-categorical mean duration as independent variables. Results show that F1, F2, and Dq gave a quite good estimation for all data analyzed. Therefore we think that the intrinsic duration of vowels can be satisfactorily estimated by means of these three variables, at least for the languages concerned.
Rate of change of fundamental frequency: A useful parameter in acoustic analysis of the human voice?
Authors: Askenfelt Anders , Sundberg Johan
Published: October 2005

The informative power of the rate of change of the fundamental frequency (RCFF), i.e., approximately the time derivative of the fundamental frequency, has been used in two different projects on the human voice quality. One project [Hammarberg et al., Acta Otolaryngol. 90, 441–452 (1980)] deals with acoustic correlates of voice disorders. It has been shown that a perceived quality, which is commonly named “roughness,” correlates with cycle to cycle variations (perturbations) in the speech waveform. The RCFF calculated over a very short time window has been used to detect those parts of the running speech which show waveform perturbations. The results suggest a correlation between the degree of “roughness” as rated by voice experts and the amount of waveform perturbation periods in the speech. In the other project [Askenfelt and Sjölin, STL/QPSR 2–3, 74–81 (1980)] an attempt was made to find a parameter reflecting voice changes associated with psychopathological depression. The average RCFF was determined from the patient's reading of a standard text during illness and after recovery respectively. Thereby, the RCFF was calculated over a time window of approximately 50 ms. The results suggest that this RCFF measure is influenced by the mental health of these patients.
Speech as a string of pulses: Pulse-coherence function
Authors: Liénard Jean-Sylvain , Manceron Frédéric
Published: October 2005

The usual methods for speech signal analysis make an a-priori distinction between voiced and unvoiced segments, which is a well known source of errors, and give a spectrum evaluation on a time interval (20 to 40 ms) larger than the largest pitch period, which eliminates most phonetically relevant information. Our approach [after J. C. Lafon, Congrès Soc. ORL, Paris (1958)], consists in a decomposition of the signal into a string of “pulses,” which are considered as distinct only if their interval exceeds 1 ms. Pitch and voicing are to be extracted later, on the basis of regularity and spectral similarity of the pulses. The work described in the present paper is done using a filterbank followed by short-time integrators. A “pulse coherence function” is defined; its maxima are used to mark the beginnings of the pulses. The synthesis experiments made using this function show that short acoustical phenomena (of plosives), noises (of fricatives), voicing and pitch are correctly reproduced.