日本音響学会誌
Online ISSN : 2432-2040
Print ISSN : 0369-4232
33 巻, 4 号
選択された号の論文の7件中1~7を表示しています
  • 竹内 章司, 粕谷 英樹, 城戸 健一
    原稿種別: 本文
    1977 年 33 巻 4 号 p. 163-172
    発行日: 1977/04/01
    公開日: 2017/06/02
    ジャーナル フリー
    In this paper the effects of the nasal cavity and the paranasal cavities on the spectra of nasal sounds are investigated. The oral output and the nasal output were measured separately as shown in Fig. 1, each of which was used for the spectral analysis. The examples of analyzed spectra of nasalized vowels and nasal murmurs are shown in Fig. 2. The anatomical structures of the nasal cavity and the paranasal cavities are discussed with the anatomical charts (Fig. 4). The physical dimensions of paranasal cavities are discussed with the anatomical charts (Fig. 4). The physical dimensions of paranasal cavities were estimated as shown in Fig. 6 using a human skull (Fig. 5). The area functions of the pharynx, the oral cavity, and the nasal cavity were determined as exemplified in Fig. 8 by applying the data published by Chiba and Kajiyama and by Fant. The frequencies of poles and zeros which specify the transfer function were calculated using the models for the productions of nasal sounds shown in Fig. 7. These calculations were carried out by computer simulation of the well-known theory of the transfer characteristics of acoustic tubes. The spectra were synthesized as shown in Fig. 9 from the frequencies of poles and zeros from simulation. These synthesized spectra are compared with the analyzed spectra shown in Fig. 2, and the nasal cavity and each paranasal cavity are discussed in detail. Especially, the zeros which appear in the low frequency region are discussed with the supplementary examinations of the spectral changes, in which the nostrils were closed as shown in Fig. 12. As the result of the discussions, we may conclude that the spectral characteristics of the nasal sounds in natural utterances cannot be fully explained by the simplified model including only the nasal cavity, and that the effects of the paranasal cavities must be also considered.
  • 村岡 輝雄
    原稿種別: 本文
    1977 年 33 巻 4 号 p. 173-182
    発行日: 1977/04/01
    公開日: 2017/06/02
    ジャーナル フリー
    Carrier quadraphonic disc technology introduced in the early seventies, underscores the importance of tracing correction because of the paricular way in which base band signals interact with carrier signals. In a carrier disc, tracing distortion not only results in the familiar degradation of base band signals, but also allows the base band to modulate the carrier components directly (UP-talk). On the other hand, methods for dealing with tracing distortion through the generation of complementary functions based upon Hunt's analysis (Eq. (4)) were developed. But Hunt's analysis is insufficient in the present disc recording technology because of omitting the tilted cutting-tracing process (Figs. 2, 3, 4). In this paper, first an extended analysis is made and a generalized equation (8) is derived. Based upon (8), the UP-talk in a carrier quadraphonic disc is represented in the general equations (17), (18), and some numerical examples are shown (Figs. 8, 9, 10, 11, 12, 13). UP-talk has the basic characteristics of frequency dependent increase by 12 dB/oct, proportionality of playback stylus radius γand carrier frequency ω_c, and inverse proportionality to the square of the groove velocity V. Next, the effects of conventional predistortion are discussed and shown insufficient because of the existence of residual distortion or UP-talk (Eqs. (23), (25). Figs. 14, 15, 16, 17). Finally a new complementary function considering the effect of the tilt is derived (Eq. (33) and the functional diagram is shown (Fig. 19)). The new distortion compensation device results in satisfactory UP-talk reduction as shown in Fig. 20.
  • 太田 光雄, 山口 静馬, 有馬 俊晴
    原稿種別: 本文
    1977 年 33 巻 4 号 p. 183-189
    発行日: 1977/04/01
    公開日: 2017/06/02
    ジャーナル フリー
    In this paper, firstly, a unified theory of the statistical treatment of the probability distribution function is introduced in the case when a general random noise of arbitrary distribution type exhibits the nonstationary property with arbitrary temporal change of various cumulants by generalizing previous studies of nonstationary properties with fluctuation of mean value and/or variance. As the result for the purpose of finding an effect of nonstationality due to temporal change of cumulants on the output probability distribution, the explicit expressions of cumulative distribution function and probability density function in the general form of statistical expansion series, taking the stationary term into the first term, are derived. The nonstationary effect caused by the change of various cumulants is concretely reflected in each expansion coefficient of the second and higher terms in the above expansion expression. The validity of the above theoretical result is also supported experimentally by the nonstationary random traffic noise observed in Hiroshima city (cf. Fig. 1). Next, a new approach toward the dynamical prediction problem of L_α is considered by use of the above universal expression of probability density function for arbitrary nonstationary random noise level. The usefulness of our theoretical prediction method is confirmed experimentally by application to an actual nonstationary random traffic noise level (cf. Fig. 2 and Table 1). The brief summary of our theoretical consideration is given below. The characteristic function for the general nonstationary random noise level with various temporal changes of cumulants ig given by Eq. (1) in consideration of the multi-variate probability density function of cumulants. In Eq. (2), using the usual integration by parts under Eq. (5), we can derive the relationship shown in Eq. (7). Thus, the probability density function for the nonstationary random noise level can be found in the general form of statistical expansion series, taking the stationary term into the first term (cf. Eq. (8) and Eq. (9) for a general case with dimensionless variable). The nonstationary effect caused by the change of various cumulants on the noise level distribution form is concretely reflected in each expansion coefficient of the expansion expression (cf. Eq. (4)). For several special cases, the expression (8) is quite in agreement with those of the corresponding expressions derived in the previous papers (cf. Eqs. (13) and (14)). When each cumulant is predicted by auto-regressive model under the error criteria shown in Eq. (16), the regression coefficient can be calculated by Eqs. (17) and (18) in the case when the third order auto-regressive model is employed. When Eq. (19) is considered under the criteria (20) as the other prediction method, then each expansion coefficient can be calculated from Eqs. (21) and (22).
  • 鎌田 弘志, 大垣 正勝
    原稿種別: 本文
    1977 年 33 巻 4 号 p. 190-197
    発行日: 1977/04/01
    公開日: 2017/06/02
    ジャーナル フリー
    The development of a transducer array for acoustical holography is described. The array consists of la 4x4 sparse planar projector array and a 32x32 dense planar hydrophone array. The elements of the proje- ctor array are "Diced and Shaded Transducers" and those of the hydrophone array are "Short-column and On-socket type Transducers". These are operated at 200kHz below the resonance frequency in the sea. Gain-phase deviations in the elements of the array determine the background noise to the holographic image signal. We realized that the standard deviation of responses was 1. O dB for the projector elements and 1. I dB for the hydrophone elements. Consequently, it is expected that the performance of the manufactured array gives an image with high quality.
  • 福田 友美子, 比企 静雄
    原稿種別: 本文
    1977 年 33 巻 4 号 p. 198-207
    発行日: 1977/04/01
    公開日: 2017/06/02
    ジャーナル フリー
    Syllable articulation score and word intelligibility score by visual, auditory and both visual and auditory reception were measured for 13 hearing-im-pared children (Table 1) utilizing a monocrome TV recorder and monitor, and the relationship between hearing loss and effect of residual hearing upon speechreading and its individual characteristics were examined. Articulation scores of vowels, consonants and syllables by both visual and auditory reception (Fig. 1) and by only auditory reception (Fig. 3) decreased with the increase of the hearing loss, while those by only visual reception (Fig. 2) showed individual difference in the ability of speechreading. The effect of residual hearing upon speechreading of syllables, vowels and consonants inversely related to the hearing loss, but the effect showed a significant individuality (Fig. 4). Correlation coefficients among syllable, vowel and consonant articulation scores (Table 2) indicate that the ability of identifying consonants was closely related to that of syllables in Japanese. The individual characteristics of identification of vowels and consonants was analyzed, classifying the confusion matrices among vowels by visual reception (Table 3) and by auditory reception (Table 4), and the confusion matrices among consonants by visual reception (Table 5) and by auditory reception (Table 6). The relationship between hearing loss and word intelligibility scores by both visual and auditory reception (Fig. 5), by only visual reception (Fig. 6) and by only auditory reception (Fig. 7), and the relationship between hearing loss and effect of residual hearing upon speechreading of words (Fig. 8) showed a similar tendency to those of the syllables. The high correlation coefficients between syllable articulation score and the word intelligibility score (Table 7) and the high rate of correct answer for number of moras in the word (Table 8) suggests the fact that the abilities of identification of syllables and words are directly related to each other. The other intelligibility score, however, was affected by the easiness of the word as well as the number of homophenous words. Based on the results (Table 11), the most effective methods of training speechreading and use of residual hearing for each subject were discussed.
  • 守田 栄
    原稿種別: 本文
    1977 年 33 巻 4 号 p. 208-211
    発行日: 1977/04/01
    公開日: 2017/06/02
    ジャーナル フリー
  • 岸 義雄, 林 義信
    原稿種別: 本文
    1977 年 33 巻 4 号 p. 212-215
    発行日: 1977/04/01
    公開日: 2017/06/02
    ジャーナル フリー
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