Stop consonants [p], [t], [k] and a fricative [s] were acoustically analyzed using a computed model of the peripheral auditory system in 12 normal subjects and 12 patients with tumors of the tongue who had undergone surgical resection and reconstruction. The model is a combination of the cochlear model that consists of 28 FIR filters (Delgutte) and the inner hair-cell/auditory nerve synapse model (Meddis), with some modification. It simulates firing of the auditory nerve in every channel related to the FIR filters in response to an input voice signal.
Phonetic characteristics of the tested consonants were more clearly visualized by observing firing patterns and voice onset time (VOT) using this auditory model than with use of the conventional soundspectrogram. In patients with tumors of the tongue, the degree of distorted articulation and the area of surgical resection were significantly related to obscurity of the phonetic characteristics of the stop consonants [t] and [k].
Acoustic analysis using this auditory model may serve as a useful tool for voice analysis in research and in the clinical field.

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In the 22 multi-channel cochlear implant system, F0 information determines the frequency of electrical stimulation, and F1 and F2 information determine the number of stimulating electrodes. We performed tests using synthetic vowels on 16 patients who had undergone 22 channel cochlear implant surgery and 6 months' speech rehabilitation. Information transmission rates were calculated to analyze the response pattern. As a result, 1) the vowel recognition ability of patients with cochlear implant surgery correlated with the number of electrodes being used. 2) The value of vowel confusion decreased so as to be separated by a pair of stimulating electrodes, and the confusion in F1 information was regarded to be less than that for F2 information.

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Acoustic rhinometry measures the cross-sectional area of the nasal cavity based on changes in acoustic impedance. The volume of the nasal cavity can be calculated by mathematical integra-tion of the cross-sectional areas. One of the advantages of this procedure is that repeated measurements can be quickly performed non-invasively. In this study, we analyzed the mecha-nisms of nasal mucosal decongestion after applying vasoactive agents.
The experiments were performed in normal adult volunteers (17 males, 3 females) who gave their informed consent to participate in this study. Three vasoactive agents (0.1% epinephrine, 0.5% phenylephrine hydrochloride, 0.5% oxymetazoline hydrochloride), two alpha-receptor antag-onists (0.2phenoxybenzamine, 0.4% yohimbine) and a local anesthetic (4% lidocaine) wereused. In order to apply the agents precisely and safely, we attached a 6mmdiameter discmoistened with 0.1ml of solution to the anterior portion of the inferior turbinate unilaterally for fifty seconds. After removing thedisc, acoustic measurements were performed for an hour. To analyze data we divided the nasal cavity into three portions, i. e., anterior, middle and posterior.
Volume changes in each portion are expressed as percentages.Immediately after applying phenylephrine and oxymetazoline, ipsilateral volume in the anteriorportion began to increase, and then extended posteriorly. The level of decongestion remained unchanged for an hour. Contralateral volume decreasedin allportions. When epinephrine was applied, mucosal decongestion occurred first followed by congestion in all portions of the ipsilateral side after 20 minutes. Mucosal congestion occurred in all portions of the contralateral side.
After applying phenoxybenzamine or yohimbine for ten minutes, we administered vasoactive agents topically. Pretreatment with alpha-1 antagonist almost totally suppressed the mucosal decongestion caused by phenylephrine and oxymetazoline. Contralateral congestion was decreased by antagonizing the suppression of ipsilateral decongestion. After application of lidocaine for ten minutes, phenylephrine still caused ipsilateral decongestion only in the anterior portion, but decongestion of the middle and posterior portion and congestion on the contralateral side totally disappeared.
These findings suggest the following conclusions: 1) decongestion evoked by adrenergic agents is probably caused by direct activation of alpha-1receptors, 2) decongestion of the middle and posterior portions is evoked by drug particles conveyed by ciliary movement, and 3) the contralateral responseisprobably related to the activation of sensory nerves on the ipsilateral side.

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A multichannel cochlear implant was performed in 8 children, and the following results wereobtained.
The surgical procedures were not as difficult as in adults, and there were few postoperativecomplications. The results of testing postoperative speech comprehension ability were examinedin three children whose course was followed for more than one year postoperatively. Somepatients had good speech comprehension ability postoperatively, and we expect to continue perform-ing cochlear implant in children.
Postoperative rehabilitation takes longer. The cooperation of physicians, audiologists, speechtherapists, school teachers and familymembers is essential, and establising a cochlear implantcenter for children would be desirable.

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We have performed cochlear implants on 6 adult prelingually deaf patients and obtained the following results.
1) The speech comprehension ability of the adult prelingually deaf patients was poorer than in postlingually deaf patients, but some patients showed better results than expected.
2) The adult prelingually deaf patients required a longer period of rehabilitation than the postlingually deaf patients. There were considerable variations in performance among the adult prelingually deaf patients.

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The aim of this retrospective study was to investigate a correlation between histopathological differentiation and metastasis in patients with carcinoma of the nasal cavity and paranasal sinuses to improve the survival.
Between 1984 and 1992, 52 cases of sino-nasal malignant tumors were treated at Kagawa Medical School Hospital. Squamous cell carcinoma was evaluated in 29 patients and undifferentiated carcinoma in five patients.
Treatment in most cases consisted of radiotherapy, 50 Gy/25 fr/5 weeks, continuous intra-arterial infusion of 5-FU 2000mg/4 weeks, and an extensive Denker's operation 2-3 weeks after the completion of radiotherapy. The 5-year survival rate was 53%, and the local control rate was 82%. Patients died of local failure (six), distant metastases (six), lymph node metastases (one) and other causes (three).
Twenty-eight patients with local control were classified into G1-2 (well-and moderately-differentiated) and G3-4 (poorly-differentiated and undifferentiated) groups. Lymph node metas-tasis was unrelated to the degree of differentiation, but distant metastasis was significantly correlated to the degree of differentiation (P=0.014). The 5-year survival rates in lymph node metastasis (n=7), non-lymph node metastasis (n=21), distant metastasis (n=7), non-distant metastasis (n=21), and the G1-2 (n=17) group and the G3-4 group (n=11) with local control were 57%, 63%, 14%, 78% (P=0.002), 72% and 44% (P=0.0384), respectively. The results of combination therapy were poor in patients with poorly-differentiated or undifferentiated carcinoma because of distant metastasis, and adjuvant chemotherapy may be necessary in such patients to prevent distant metastasis.

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There has been a great deal of controversy concerning the development of pneumatization in the temporal bone. Many reports on the size of the mastoid air cell system have been discussed a planimetric X-ray method, however, there have been no techniques for direct volume measurement based on high-resolution computed tomography (CT). Discussion of the relationship between ear disease and pneumatization of the temporal bonerequires three-dimensional measurement of the temporal bone in vivo. Recently, we developed such a technique by using digital image processing to measurethe volume of the mastoid air cell system. With this technique, only the air cells and tympanic cavity, with a gray scale level similar to air outside the skull were easily selected on the CT films. Then, after image processing called "thresholding", only the areas and volumes of these extracted pneumatized parts were calculated. The volumes of the pneumatized parts of the temporal bone were calculated separately as partial volumes divided by several CT planes. The sum of the partial volumes was calculated as the total volume of the aerated cavity. This technique also made it possible to reconstruct a three-dimensional (3D) model of the air cell system for visual presentation.
CT images of 43 normal temporal bones were analyzed. The average volume temporal bone pneumatization (including air cells and tympanic cavity) was about 6ml. There were no differences between pneumatization on the two sides in either sex. Comparisons of partial volumes of pneumatization in the temporal bone revealed that the volumes of portions including the tympanic cavity and its surrounding air cells and those of the antrum and its surrounding air cells were larger than those of other portions. 3D models of the air cell system revealed a variety of shapes. These findings indicated that this technique is not only useful for quantitative analyses but for easy subjective morphological analyses.

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The patient was a 41-year-old man who lost his hearing on the left at 7 years of age and on the right at 34 years of age due to meningitis. At 35 years of age a single-channel cochlear implant, 3M/House design, was implanted. Five years after the initial operation, the singlechannel prosthesis was replaced by a multichannel device (Cochlear Corp.) because of the patients earnest wish to obtain better hearing. Explantation of the short electrode of the single-channel device was easy, but reimplantation of the longer electrode of multichannel device was somewhat difficult, probably because of the presence of the peri-implant fibro-osseous cuff in the Scala tympani. Single-channel and those of the multichannel speech data were compared in relation to performance in the same individual. The reimplanted multichannel device was equivalent to or outperformed the original 3M prosthesis. The patient preferred the hearing afforded by the multichannel device.

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We assesed 53 patients with acute low-tone sensorineural deafness (LTSD) over the past 10 years using the transtympanic-electrode technique of electrocochleography. The audiometricdiagnostic criteria were as follows: Average hearing level at the lower two frequencies (250, 500Hz) greater than 30dB, and of the higher three frequencies (2, 4, 8kHz) less than 20dB. Patients were divided into three groups on the basis of their electrocochleographic findings; 33 cases of the endolymphatic hydrops type, 17 cases of the hair cell damage type and 3 cases of the neural damage type. The outcome of these patients was assessed together their electrocochleogra phic findings.
The results obtained were as follows:
1) Most of the improved cases were of the endolylmphatic hydrops type and in females in their twenties. All of the improved cases showed high AP and -SP amplitude, but not dominant -SP, and exhibited slight prolonged AP latency. Satisfactory CM responses at 500Hz were also found.
2) Most of the hair cell damage type exhibited no change, and some unrecovered cases of the endolymphatic hydrops type progressed to Meniere's disease.

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Lymphocytes in the lingual tonsil were analyzed using monoclonal antibodies to cell surface markers.
Immunohistologic staining of lingual tonsillar tissue showed localization of the various lymphocyte subsets in the germinal center, mantle zone, and inter-follicular area.
Populations of lymphocyte subsets, i. e., T cells, B cells, CD4 positive cells, CD8 positive cells, αβT-cells, γδT-cells, and NKcells were assessed by laser flow cytometry analysis, and we compared the following tissues: peripheral blood, lingual tonsils, palatine tonsils, and pharyngeal tonsils (adenoids).

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