The pathogenesis of fluctuating sensory-neural hearing loss was classified into two types. In the first type, both hair cells and nerve cells are normal and the auxiliary tissues of the inner ear only are reversibly involved. By contrast, in the second type, hair cells and/or nerve cells themseles are involved by reversible degeneration but the auxiliary tissues are normal. In the former, especially the stria vascularis was thought to play an important role.
Cochlear potentials, Preyer's reflex and post-rotatory nystagmus in guinea pigs were recorded under application of anoxia and intravenous administration of furosemide. The 8th nerve action potential of the Ménière's disease was also examined and analysed by means of an anlog averaging computor.
These experimental results induced the conclusion that vascular or metabolic insufficiency of the stria vascularis caused a reversible hearing threshold elavation of 30-35dB for all frequencies, and then change of ion composition and volume of endolymph resulted in a reversible inner ear conductive deafness.

抄録全体を表示

HRTFs (Head-Related Transfer Functions) describe transfer functions of sound propagation paths from a sound source to listener's external ears. Conversely, a perceived sound position can be arbitrarily controlled by convolving of impulse responses corresponding to HRTFs, i.e., HRIRs (Head-Related Impulse Responses), to a sound source. Such a system is called virtual auditory display (VAD). To realize high-precision VAD systems, responsiveness to head movement, low system latency and representation of strict HRIRs are necessary. We therefore developed a high-precision software VAD system realizing these requirements on Linux operating system (Kernel 2.6). In this VAD system, total system latency is about 12 ms. HRIRs to use in our system are measured from 1226 points and inteplolated spatially and (optional) temporally. Then, it was confirmed by a listening experiment that it was difficult for listeners to sense a system latency on our proposed VAD system.

抄録全体を表示

インタネット上で個人放送局を開設するための技術解説を行う.第2回はストリーミング技術の後半と, 具体的なソフトウェアの実装方法について説明する.次回 (最終回) は, 代表的なストリーミングソフトウェアの使用方法について説明する.

抄録全体を表示