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Factors affecting subjective tinnitus pitch and tinnitus tonality were analyzed with the use of the quantitative method II. Ninety-one patients with unilateral tinnitus of a single kind were studied. Major factors affecting subjective tinnitus pitch were pitch matched frequency, age, puerility and impurity of tinnitus tonality, and loudness of tinnitus. In addition, major factors affecting puerility and impurity of tinnitus tonality were pitch matched frequency, loudness of tinnitus, and nature of the test tone. Furthermore, subjective puerility of tinnitus was associated with middle-pitched frequency and high-pitched frequency, and a loudness level of tinnitus between 25 and 49 dB HL. Whereas impurity of tinnitus was related to low-pitched frequency and noise of the test tone. These results may contribute to the clinical evaluation of tinnitus.

Factors affecting annoyance due to tinnitus were analyzed using quantitative method II. Ninety-one patients with unilateral tinnitus of single kind were studied. Major factors affecting annoyance due to tinnitus were found to be subjective loudness of tinnitus, age, degree of hearing loss, tinnitus loudness level in dB HL, pitch matched frequency, puerility and impurity of tinnitus tonality, and subjective tinnitus pitch. Increased annoyance due to tinnitus was associated with an age of 30-49 years, a tinnitus loudness level between 25 and 49 dB HL, a tinnitus loudness level more than 15dB SL, impurity of tinnitus tonality, larger subjective loudness, and high-pitched tones above 4000Hz. Decreased annoyance due to tinnitus was related to the smaller subjective loudness, loudness level below 25dB HL, low-pitched tones below 250Hz, and purity of tinnitus tonality. Our results suggest that these factors are responsible for individual differences in annoyance caused by tinnitus.

A large negative deflection with a latency of 3 msec was observed in the auditory brainstem response (ABR) waveforms of 48 patients (6.5%), [59 ears (5.8%)] in 740 patients with profound peripheral deafness (1,009 ears) between 1978 and 1990 at our department. This negative deflection was termed the "N3 potential." We reviewed some of these patients and discuss some common characteristics found in abnormal ABR waveforms. We also inquired into the conditions and origins of these potentials. Although virtually all patients were less than 10 years of age, the N3 potential was also observed in the ABR waveform of adult patients. There were no sex differences. In the majority of patients audiograms showed no response to the maximum output of an andiometer in the high frequency range and a residual response in the low frequency range. The most common cause of deafness was "unknown" in children, and "sudden deafness" in adults. The N3 potentials were noted at intensities of 80 dBnHL or greater. A high repetition rate (83.3/sec) of the click stimulus influenced the latency and amplitude of the N3 potential. As the stimulus intensity increased, the amplitude of the potential increased, and the latency decreased. The potential was replicated on retesting within less than a month. The N3 potential had a consistent latency and amplitude over the scalp. We conclude that the N3 potential was a physiological "neural" response evoked by a loud sound rather than by an electrical artifact. The N3 potential was most likely not an auditory evoked response or a response from a semicircular canal, because of the 3-msec latency and sharpness of the waveform, with lack of vertigo. The results suggest that the N3 potential may be a saccular acoustic response.

Cellular DNA content and succinate dehydrogenase activity of 92 human head and neck (34 laryngeal, 24 pharyngeal, 21 oral cavity, 13 maxillary) squamous cell carcinomas were examined, and DNA ploidy status and chemosensitivity were analyzed and compared. DNA aneuploidy was observed in 54 tumors (58.7%). The aneuploid pattern was most common in tumors of the maxillary sinus (84%), and least common in tumors of the larynx (41.3%). Histologically, aneuploidy was detected in 71.4% of poorly-differentiated, 63.8% of moderately-differentiated and 37.5% of well-differentiated squamous cell carcinomas. There was a statistically significant difference between the survival rates of patients with diploid and aneuploid patterns. Chemosensitivity was determined by exposing fresh tumor material to five antitumor drugs: adriamycin (ADM), cisplatin (CDDP), carboquone (CQ), 5-fluorouracil (5-FU) and mitomycin C (MMC). The average decrease in succinate dehydrogenase (SD) activity was 49.8% with ADM, 33.6% with CDDP, 39.9% with CQ, 68.4% with 5-FU and 45.5% with MMC. Histologically, poorly-differentiated squamous cell carcinomas were most sensitive to these five antitumor drugs. We also compared average SD activity in tumors from different organs and found that pharyngeal tumors tend to be most sensitive to these drugs, except for MMC. The chemosensitivity of a tumor with DNA diploidy tended to be higher among well- and moderately-differentiated squamous cell carcinomas. In contrast, tumors with DNA aneuploidy tended to have higher chemosensitivity in the poorly-differentiated type. The results of this study indicate that simultaneous analysis of DNA ploidy and chemosensitivity will be helpful in understanding the characteristics of tumors as well as in predicting the most effective chemotherapy agents for head and neck cancer patients.