Search

This investigation examined the effects of otitis media with effusion (OME) and its associated fluctuating conductive hearing loss on the perception of phonological and morphophonological /s/ and /z/ in young children. We predicted that children free of OME (OME-) would perform better than children with histories of OME (OME+). We also predicted that for the OME+ group morphological perception would be harder than phonological perception, because the former category carries an additional linguistic load (i.e., plurality). Sixteen children, ages 26 to 28 months (M = 26.5, SD = 0.6) were divided into two groups, the OME- (n = 8) and OME+ (n = 8) based on OME history during the first year of life. Subjects in the OME- group were free of the disease for 4/5 visits and pure tone average (PTA) was 12.6 dB HL (SD = 4.8). Subjects in the OME+ group had the disease on 3/5 visits and PTA was 23 dB HL (SD = 2.7). Experimental stimuli were six monosyllabic novel word-pairs. Members of each word-pair differed only in the presence of final voiced or voiceless fricative, marking the targets phonologically (e.g., [g [symbol: see text]]/[g [symbol: see text] s] as in 'law', 'loss') or morphophonologically (e.g., [daep]/[daeps] as in 'map' 'maps'). Subjects were taught the unfamiliar word pairs using a fast mapping procedure. Perception was tested with the bimodal preferential looking paradigm. Children in the OME- group performed significantly better than their OME+ counterparts. Individual word-pair analyses showed that OME+ group performed more poorly than the OME- group on one phonological and on two morphological targets, all ending with [s]. For the OME+ group, targets with final [s] posed greater difficulty than those with final [z], especially on morphophonological plural-(s) targets. The results suggested that the fluctuating hearing loss associated with OME might have a negative impact on speech perception.

Recent investigations of children with specific language impairment (SLI) have found deviant anatomical asymmetry of the perisylvian cortex. These studies argue that this deviant anatomical asymmetry is linked to the language disorders of SLI children. To date no studies have examined whether deviant functional asymmetry underlies the processing of spoken language in these children. In the current study, brain-electrical activity was recorded from 31 scalp sites while children with SLI listened to auditorally presented stories and two different nonsense contexts. Electrical activity was time-locked to the grammatical word "the" in these contexts. The SLI children showed reversed asymmetry compared to control children from 200 ms to 400 ms in processing "the" in all contexts. More specifically, they showed depressed processing at the left temporal scalp site (T7) and enhanced processing at the right temporal site (T8). The second spatial derivative (the Laplacian) of the voltage activity was calculated to remove constant voltage potential and uniform changes in voltage potential across the scalp. The Laplacian analysis indicated that the sources of the positive electrical activity seen at the temporal electrode sites T7 and T8 are the lateral surfaces of the temporal cortices. A comparison of the scalp topography of the voltage potentials and Laplacian also suggests that children with SLI lack some contribution from a deep neural generator, possibly in the hippocampus or basal ganglia. This investigation is the first to demonstrate a direct link between deviant neurophysiological asymmetry and the processing of spoken language in children with SLI.

Deviant anatomical asymmetry of perisylvian cortex is argued to be linked to specific language impairment (SLI). However, no studies have examined whether deviant functional asymmetry underlies the processing of spoken language. In the current study, brain-electrical activity was recorded from 31 scalp sites to the function word 'the' embedded in auditorally presented stories and nonsense contexts. The SLI children showed reversed asymmetry at electrode sites over temporal cortex compared to control children in processing this word in all contexts. They also appear to lack some contribution from a deep neural generator in processing 'the' in the story. This investigation is the first to demonstrate a direct link between deviant neurophysiological asymmetry and the processing of spoken language in children with SLI.

Two groups of children, with (n = 7) and without (n = 7) first-year histories of otitis media, were participants in a longitudinal study that included periodic audiological and medical evaluations during the first year of life. At age 9, these children were tested on a series of speech perception and verbal short-term memory tasks using stimuli of varying degrees of phonetic contrast. Although the otitis-positive group performed less accurately than the otitis-free group, the pattern of errors was the same for the two groups. The performances of the children with and without positive histories of otitis media were negatively affected by an increase in phonetic similarity of the stimulus items. The two groups, however, did not differ on identification or on temporal-order recall when the speech sounds were differentiated by multiple features. These findings provide evidence of subtle, long-term effects of early episodes of otitis media on phonological representations and on working memory.

Purpose: The incidence of cardiotoxicity and clinical cardiac events following mantle irradiation (RT) in patients with Hodgkin's disease using modern techniques is controversial. The use of quantitative, prognostically validated noninvasive tests to assess systolic and diastolic cardiac function and regional myocardial blood flow may reveal preclinical abnormalities associated with subsequent clinical events of myocardial infarction, cardiac death, or angina. The goals of this study are to determine, through noninvasive measures, the presence and time course of alterations in cardiac systolic and diastolic function and of relative myocardial blood flow in long-term survivors of Hodgkin's disease, and assess their correlation with subsequent clinical cardiac end points., Methods and Materials: Equilibrium radionuclide angiocardiography (ERNA) was used to assess left ventricular (LV) systolic and diastolic function by measuring LV ejection fraction (LVEF) and peak filling rate (PFR), respectively, in patients without known ischemic heart disease who received RT. Electrocardiography was performed to assess electrical cardiac function under conditions of rest and either exercise or dipyridamole vasodilator stress. Quantitative rest/stress myocardial perfusion imaging with thallium-201 and/or Tc-99m sestamibi was used to assess myocardial perfusion. Patients at least 1.0 year after RT were eligible if they were <50 years old at RT, had no known cardiac disease, and remained free of clinical recurrence of Hodgkin's disease. Fifty patients, ages 10.2-46.1 years (mean 26.0 +/- 8.6) at RT, were tested 1.1 to 29.1 years (mean 9.1 +/- 7.5) after RT. Seventeen of these patients were tested two times separated by 1.1 to 8.1 years. The mean central cardiac RT dose was 35.1 +/- 7.8 Gy (range 18.5-47.5) in daily 15-2.0 Gy fractions. Twelve patients were concomitantly irradiated to the left ventricle, usually through partial transmission left lung shields (mean 17.0 +/- 2.2 Gy, range 14.3-21.3)., Results: No patients had signs or symptoms of cardiac disease at the time of evaluation. The mean LVEF at the time of initial testing was 59.6 +/- 6.2% (n = 50; range 42-73%; normal > or =50%), and the mean peak filling rate (PFR) was 3.46 +/- 0.88 end diastolic volumes per second (EDV/s) (range 1.5-5.4 EDV/s; normal > or =2.54 EDV/s). The 12 patients also treated to the left ventricle had a normal mean ejection fraction that was lower (56.6 +/- 5.0%) than that of the other 38 patients (LVEF = 60.6 +/- 6.3%, p = 0.051) when initially evaluated. Average PFR was similar in the two groups. For the 15 patients who had repeat tests, changes in LVEF were generally modest in individual patients, and there was no change in the group mean. For all patients, no significant association was found between cardiac function indices and age at RT, dose, or interval from RT to testing. Myocardial perfusion scintigraphy demonstrated mild ischemia in one or more segments in two patients, and borderline normal perfusion in three patients. Rest and stress ECG testing demonstrated mild repolarization abnormalities in three, and one patient was abnormal at rest and had nondiagnostic changes with stress., Conclusions: Patients irradiated to the heart incidental to the treatment of Hodgkin's disease using modern techniques have generally normal measures of left ventricular function and myocardial perfusion. Modest differences in the normal left ventricular ejection fraction observed may be attributable to the cardiac volume irradiated. Some patients may manifest improved cardiac function as time from RT elapses, while a significant deterioration of ejection fraction was not observed and reduction in diastolic peak filling rate is uncommon. The previously reported increased risk of cardiac death may relate to use of older techniques of RT employing higher doses and lack of cardiac shielding, and uncontrolled patient selection with additional behaviors and cardiac risk factors.

The influence of information level on the production accuracy of 20 children (22 to 28 months) was examined. The data were children's productions of nouns in sets of utterances referring to triplets of pictures representing noun-verb-noun utterances. In each triplet one noun remained the same, thus decreasing in information value from the first to the third picture (new, moderately old, and old information). Words representing new information were produced more accurately than words representing old information. The types of errors did not differ. Further evidence of this effect was provided by an examination of the duration of new versus old word productions by 12 of the children. Productions encoding new information were consistently longer on average than those encoding old information. The result provide experimental evidence of an effect observed in adults that indicates early sensitivity to information level. However, because of the children's young age, the effects are characterized as a speaker-internal process that only serendipitously corresponds to listener needs.

This study was designed to assess the contribution of clinical, electrocardiographic and exercise hemodynamic variables to the prediction of normalization on resting reinjection scintigraphy of persistent thallium-201 (201Tl) myocardial perfusion defects seen with exercise and 2- to 4-hour delayed (redistribution) imaging. To evaluate this contribution, we studied 159 consecutive patients with persistent 201Tl myocardial perfusion defects on routine exercise and 2- to 4-hour-delayed scintigrams at the University of Rochester Medical Center who were classified as having moderate or greater ischemic normalization (group 1, n = 76) or minimal to no ischemic normalization (group 2, n = 83) by reinjection scintigraphy. Multiple logistic regression analysis with backward elimination was used to model the effects of clinical, electrocardiographic and exercise hemodynamic data on the odds ratio of a normalized defect. No difference was observed in the two groups with regard to gender, angina on exertion, rate-pressure product, exercise duration, resting or exertional ischemic ST changes on electrocardiogram, presence of Q waves or left ventricular hypertrophy on baseline electrocardiogram, or total number of stress thallium defects (2.8 +/- 1.5 segments). No single variable or combination of variables discriminated between groups 1 and 2 by logistic regression analysis. We conclude that defect normalization seen on resting 201Tl myocardial perfusion scintigraphy is prevalent in patients with persistent defects on routine exercise and delayed myocardial perfusion scintigraphy, and was not predictable from available clinical, electrocardiographic and exercise hemodynamic variables.

The acoustic characteristics of stress were examined in young children's productions of minimal pairs of novel words (e.g., sofi versus so'fi). Fourteen 2-year-olds participated as subjects. Their productions were analyzed in terms of vowel duration, syllable duration, peak amplitude, and peak fundamental frequency. The analyses revealed that children produced stressed and unstressed syllables distinctly along each of the dimensions examined. The absolute and relative (unstressed/stressed) values of the children's productions were compared to those of the single adult experimenter, who modeled the novel words, permitting a unique comparison of input to children's productions. One systematic difference was the relative values; the children's stressed and unstressed syllables were less distinct than the adults along each of the acoustic correlates. Furthermore, the acoustic features of both stressed and unstressed syllables appear to be subject to developmental change. The results are discussed in terms of their implications for young children's production capabilities and for the relationship between input and children's production characteristics.

This investigation examined the influence of metrical patterns of words (syllable stress and serial position) on the production accuracy of 20 children (22 to 28 months). The data were productions of six pairs of individualized two-syllable experimental words that referred to unfamiliar objects. Members of each pair differed only in the placement of stress (e.g., ['soti] vs. [so'ti]). Unstressed syllables were much more likely to be omitted, particularly at the beginning of words. Very few stressed syllables and unstressed second position syllables were omitted. One fourth of the word initial unstressed syllables were omitted. Consonant omissions, though few in number, tended to occur in initial position. Assimilation errors were not influenced by stress or serial position. When segmental errors due to syllable omissions were excluded, other consonant errors were not affected by stress or serial position. These findings indicate that young children's productions of syllables are influenced by the metrical patterns of words. However, the trochaic pattern of English is a statistical tendency, not an absolute constraint on two-syllable words. Metrical pattern also does not affect the consonant accuracy in syllables produced.

Young children's productions of novel words were used to investigate the influence of word familiarity on vowel and word duration. Ten children, 18 to 21 months old, produced tokens of phonologically individualized words (from one to four words) over 12 experimental sessions. Comparisons of means for the individualized words revealed that productions in the second half of the sessions were significantly shorter (both in their vowel and overall duration) than those in the first six sessions. When mean durations of productions were derived for each child, the effect held for word durations. Vowel durations differed in the same direction, but the difference was not statistically significant. Under these controlled conditions, familiarity seemed to influence the duration of early productions of novel words. These findings are discussed as evidence of word-specific motor maturation in early lexical acquisition.

Objectives: This study evaluated the value of noninvasive testing to predict cardiac events in patients with stable coronary disease after hospital admission (and risk stratification) for an acute coronary event., Background: Exercise testing with thallium perfusion imaging identifies patients with obstructive coronary artery disease and has been used to stratify patients after myocardial infarction. Its usefulness for predicting cardiac events in patients with stable coronary disease after recovery from an acute coronary event was explored., Methods: Nine hundred thirty-six patients were enrolled 1 to 6 months after hospital admission for a coronary event. Patients underwent exercise treadmill testing with planar thallium-201 scintigraphy and were followed up for an average of 23 months (range 6 to 43). End points were 1) unstable angina requiring hospital admission, nonfatal myocardial infarction or cardiac death; 2) nonfatal infarction or cardiac death; or 3) cardiac death alone., Results: Twelve patients died of cardiac causes (1.2%); 32 had a nonfatal myocardial infarction (3.4%); and 79 patients (8.4%) developed unstable angina in the first year. Exercise testing improved proportional hazards models constructed from clinical variables for all three end points (p < 0.05). The perfusion scan further improved models for the end points (nonfatal infarction or cardiac death and cardiac death alone, p < 0.05). However, the exercise test with or without thallium added little to the overall prediction of primary events (area under the receiver operating curve increased from 0.649 to 0.663), and only 2% to 13% of patients with abnormal results either had a nonfatal infarction or died., Conclusions: Thallium-201 scintigraphy and exercise testing variables identify patients at risk for subsequent cardiac events. However, the poor predictive performance of these tests in this group of patients with stable coronary disease severely limits their usefulness. These results suggest a limited role for exercise and thallium testing in predicting cardiac events in patients with known coronary disease.

Cumulative trauma disorders have increased five-fold since 1979 and now account for up to 47% of workplace injuries. Nerve entrapment, tendonitis, and other soft tissue injuries are the most common diagnostic groups. Both occupational and non-occupational factors contribute to the etiology of these disorders. Epidemiology, differential diagnosis, and interventions for treatment are reviewed.

The liquid, fricative, and affricate sounds in the phonological system of a single misarticulating child were the focus of converging analyses. These analyses included structured measures of perceptual and productive skills, language sampling, and acoustic analysis of seemingly homophonous forms. The results of perceptual and productive tasks indicated that the child's perception of certain sounds was superior to his productions, but for other sounds, productive skill was superior to perceptual performance. This child's errors of production could be attributed to nonadultlike underlying representations. A two-lexicon model of underlying representation best accounted for the data. The findings led to inferences about the child's underlying perceptual and articulatory knowledge of fricative, affricate, and liquid sounds.

The anthracycline antibiotics, daunorubicin, doxorubicin, and the newer derivatives, are important components of many antineoplastic chemotherapeutic regimens. Their usefulness is limited by their cardiotoxicity. Sequential monitoring of cardiac function of patients undergoing chemotherapy allows identification of subclinical cardiotoxicity. In many patients monitoring can thus guide the modification of the chemotherapy to minimize cumulative cardiotoxicity, reducing acute and long-term clinical and subclinical sequelae. Such monitoring also aids in the comparison of cardiotoxicity produced by different drugs and different methods and schedules of drug administration. The considerable variability of monitoring regimens between institutions and in the literature has detracted from its usefulness. The Cardiology Committee of the Childrens Cancer Study Group has, therefore, reviewed the field and has formulated recommendations for standardized noninvasive monitoring of children during and immediately after chemotherapy and for the modification of the chemotherapy where indicated.

We previously reported that 1 week of propranolol treatment (160 to 240 mg/d, orally) reduced resting metabolic rate (RMR) an average of 9% in healthy men. To determine whether this response was caused by the 25% reduction in serum triidothyronine (T3), rather than beta-adrenergic blockade, we examined the effect of nadolol on RMR in five healthy men. Nadolol is a nonselective beta-adrenergic antagonist that does not affect T3 production. After 6 to 10 days of nadolol treatment (240 mg/d), mean postabsorptive RMR declined 7% (P less than .01), with no significant change in serum T3 or thyroxine (T4) concentrations. This effect is significantly different from that of a hospitalized control group that received no drug and had no change in mean RMR, and was not different from the response to propranolol (previously published data). Nadolol slightly reduced the mean thermic response to a meal (12%), but this effect was not statistically significant. Mean postprandial RMR was 8% lower after nadolol treatment (P less than .01), mainly because of the reduced postabsorptive RMR, rather than a change in the response to the meal. These data suggest that beta-adrenergic activity makes a small but significant contribution to resting energy expenditure in man.

Electric sympathetic block is the procedure whereby blockage of the sympathetic nerve fiber is achieved by applying controlled electrical pulses via electrodes placed on the skin. An electric block of the sympathetic fiber can occur with a direct monophasic current to achieve an anodal block, a middle-frequency or Endosan current to effect sustained depolarization, or an interferential current to achieve a fatiguing effect. The physics and theoretical framework underlying the currents used in this procedure will be reviewed.

We evaluated systolic and diastolic indices of left ventricular performance by radionuclide angiocardiography and myocardial perfusion with exercise/rest thallium scintigraphy in 16 patients previously irradiated for Hodgkin's disease. These commonly used indices of left ventricular (LV) performance included LV ejection fraction (LVEF) as a measure of systolic function, and LV peak filling rate (PFR) as a measure of diastolic function. The presence of coronary artery disease (CAD) was evaluated by ECG treadmill testing (13 patients) and by quantitative planar thallium scintigraphy (12 patients). Patients were 16-38 years old (mean 24.9 +/- SD 6.2) at the tim eof irradiation, and were evaluated 2.5-21.5 years (mean 9.3 +/- 6.3) after radiation therapy (RT). RT was delivered with beam energies of 2-18 MV, equally weighted AP-PA mantle fields with both fields treated daily for most patients (13 patients), and fraction sizes of 1.5-2.0 Gy. Six patients received radiation to th entire cardiac volume, most commonly via left-sided partial transmission lung blocks (PTLB). Patient data were analyzed according to the volume of heart treated. Individuals who had the entire cardiac volume irradiated were assigned to group I (N = 6), and those patients who had some portion of the heart shielded throughout treatment comprised group II (N = 10). In this series, no perfusion defects were evident in either group by quantitative planar thallium scintigraphy. Mean LVEF for all patients studied was 60% (normal LVEF greater than or equal to 50%). Patients in group I had a lower mean LVEF than those in group II, 55 +/- 4% versus 63 +/- 6% (p = 0.01). Mean PFR for all patients studied was normal at 3.5 EDV/sec (normal PFR greater than or equal to 2.54 EDV/sec). Patients in group I had a lower mean PFR than those in group II, 3.0 +/- 0.6 vs 3.8 +/- 0.7 EDV/sec (p = 0.04). Thus, patients irradiated to large cardiac and pulmonary volumes had lower LVEF and PFR within the normal range compared to patients who had some portion of the cardiac volume shielded. These differences are statistically significant in the relatively small groups studied but do not appear to be associated at the present time with clinically significant effects.

Electric sympathetic block is the procedure whereby sympathetic nerve fibers are blocked by application of controlled electrical impulses via electrodes placed on the skin. Methods of measuring the extent of sympathetic blockade and a clinical study using bipolar middle frequency currents to achieve electric sympathetic block are presented. Fifteen of 20 (75%) patients who underwent a 1-week series of electric sympathetic blocks reported at least 75% subjective relief from sympathetically mediated pain after completion of the series.

An optimal method for determining left ventricular ejection fraction (LVEF) by echocardiography should be rapid, reliable, and widely applicable in order to be utilized routinely in a busy clinical laboratory. Most methods reported in the literature are reliable in selected, high-quality echocardiograms. Most require off-line computer analysis and are time-consuming and poorly suited to the routine of a busy laboratory. We compared in a blinded manner several echocardiographic methods of LVEF determination with the ejection fraction obtained by equilibrium radionuclide angiography (ERNA) in 44 patients unselected for image quality. Echocardiographic methods included: [1] cubed M-mode formula; [2] Teichholz M-mode formula; [3] subjective estimation of LVEF from two-dimensional echocardiographic videotape; [4] area-length method in one four-chamber view; [5] average of area-length method in three four-chamber views; [6] average of area-length method in four-chamber and two-chamber views (one beat each); [7] subjective estimation from stored videoloop of four-chamber and two-chamber view. In 30 cases M-mode tracings were available for analysis. In only 23 of the 44 patients were the apical views suitable for quantitative analysis. The ERNA ejection fraction was 44 +/- 17% (mean +/- 1 SD). The best echocardiographic correlation with ERNA ejection fraction in each patient subgroup studied was obtained by method 3. We concluded that subjective analysis of the videotaped study by an experienced cardiologist/echocardiographer provided the best estimation of ERNA ejection fraction. More time-consuming and costly computer techniques yielded a worse estimate.

The symbolic play of 15 normally developing (CA, 16-22 months) and 15 language-impaired children (CA, 32-49 months), whose productive language skills were at the single-word utterance level, was compared. Symbolic play was assessed formally through the Symbolic Play Test and informally through the observation of spontaneous play. The language-impaired children were found to be developmentally advanced when compared to the language-matched normal children in the level and direction of their symbolic play. Relative to age norms, however, the language-impaired children evidenced deficits in symbolic play. Thus, their linguistic and symbolic play abilities were not equally impaired. These findings are discussed in terms of their implications for the relationship between symbolic play and language and for the nature of specific language impairment.

Two studies are reported in which homonymy in the speech of children with specific language impairment (SLI) was examined. In the first study, the degree of homonymy reflected in the speech of 14 SLI children was found to resemble that seen in the speech of a group of language-matched children with normal language (NL). Within each group there was considerable variation in the degree of homonymy observed. An examination of the sound changes that contributed to the children's use of homonymy suggested that homonyms arising from prevocalic voicing were more frequent in the speech of the NL children. The second study represented a more systematic examination of prevocalic voicing differences between NL and SLI children. Minimal pairs differing only in the voicing feature of the initial consonant were produced by four SLI and four language-matched NL children. The SLI children showed greater ability to distinguish the minimal pairs by means of a voiced-voiceless initial consonant contrast, as measured by voice onset time as well as by phonetic transcription. The linguistic and neuromotor factors contributing to the findings are discussed.

Two young patients with dilated cardiomyopathies associated with long-term use of cocaine are described. A 42-year-old male cocaine abuser with normal coronary arteries experienced recurrent myocardial infarction, with development of a dilated, globally hypocontractile left ventricle. The second patient, a 28-year-old woman with a prominent history of inhaling vaporized cocaine ("free-basing"), presented with symptoms and signs of biventricular heart failure and was found to have a dilated cardiomyopathy. The clinical spectrum of cocaine cardiotoxicity is reviewed, and pathophysiologic mechanisms of cocaine-induced cardiomyopathy are discussed. Long-term cocaine use may cause dilated cardiomyopathy and recurrent myocardial infarction, even in the absence of atherosclerotic epicardial coronary artery disease.

Leucine absorption across the mechanically obstructed rat intestine was studied by in vivo and in vitro techniques. It varied between the early (after 2 h) and late (after 18 h) phases of the obstruction. During the early phase there was a reduction in mucosal uptake and in net absorption of the amino acid. At 18 h the inhibition in mucosal uptake was more prominent both above and below the occlusion site but net absorption was only reduced below the obstruction and was relatively unaffected above it. Mannitol and nonmediated leucine absorption were also increased above the obstruction. The findings during the late phase suggest the presence of an increase in leucine permeability across the intestine above the occlusion site. The observed normal rate of net leucine absorption across this segment is thought to be due to enhancement in intestinal diffusion which could be masking the depression in mucosal uptake.

The influence of an adult-child discourse structure on the production of early word combinations was examined in language-impaired children. The subjects were 10 children (2:8-3:4) at the single-word utterance level. Eight of the children were engaged in 10 experimental sessions utilizing vertical structures (e.g., Adult: "Who's this?" Child: "Daddy." Adult: "What's Daddy throwing?" Child: "Ball." Adult: "Yeah, Daddy's throwing the ball."), while the remaining children, serving as controls, were engaged in an alternate activity. Examination of pretest and posttest data as well as session data revealed a substantial increase in the number of multiword productions for most of the children in the experimental group but not for the children serving as controls. These findings indicate that vertical structures have a facilitating effect on the multiword productions of language-impaired children comparable to that found in an identical procedure with normally developing children. The use of a naturally occurring adult-child discourse structure as an intervention procedure is discussed.

Young children sometimes make use of unusual phonological patterns even when they already possess the appropriate sound or a suitable substitute in their phonological systems. In this investigation, we attempted to determine whether in such instances unusual sound changes enable children to avoid potential homonymy with other words in their lexicons. Novel words were presented to children, half serving as potential homonyms, half as unlikely homonyms. The children's acquisition of these words was monitored. For a group of normally developing children, unusual sound changes were found to be more frequent in the words with the potential for homonymy. In contrast, a group of children with specific language impairment showed the same degree of unusual usage for both types of words. The findings suggest that children with specific language impairment are especially limited in their ability to capitalize on the phonetic regularities of the language.