MPEG Variable-Rate Audio-Visual Player

Support of interpretation, program editing and content retrieval


Block diagram of audio-video speed converter for MPEG data files
The quality of recorded speech is degraded when using slow or fast-forward playback. To cope with this problem, a variable-rate player for MPEG audio and video, which can 'boost' the intelligibility of variable rate audio playback has been developed. It is implemented on a PC as an application program and should be useful for not only professional users but also general users.
The player utilizes "speech rate conversion technology" developed at STRL. This technology enables the user to adjust the speech rate to the desired value while retaining the original voice quality. Combining this technique with the variable-rate playback function of MPEG video provides variable-rate natural sound synchronized with the picture. The player's features are as follows:
  1. It can continuously change the playback rate up to four times normal speed without degrading the quality of speech.
  2. It makes speech more intelligible even at four times normal playback rate by slowing the speed locally at the start of sentences or where pitch is high, while shortening pauses such as those for breathing.
  3. It provides natural sound at a slow playback rate, which is valuable for students who want to learn foreign languages on their PCs.

The variable-rate playback function also has many potential applications other than in program production and broadcasting. At present, translation of overseas news usually involves reviewing the source material on a VCR and then interpreting and transcribing the content. To support this type of work, we will continue to develop the variable-rate audio-visual player.



High-Performance Ultra-small IC Microphone

STRL has developed a condenser-type IC microphone with superb characteristics. In contrast with conventional microphones, which have many metal and resinous parts, the IC microphone is produced from silicon wafers through a continuous micro-machining process that is based on LSI manufacturing technology. This allows us to consistently fabricate a high-performance ultra-small microphone at a low-price.
The microphone's design also has a large degree of freedom because of the unique manufacturing process of the condenser, which uses a multi-layered substrate whose thickness can be controlled. This makes possible production of microphones having optimum shapes and characteristics for a wide range of applications, from high-performance professional-use microphones for interviews and recording music, to microphones for consumer appliances such as portable terminals.

Note: Tohoku University cooperated in the development of the technologies used to make the new microphone. Their contributions include anisotropic etching, a technology used to carve patterns only in the direction normal to the surface of the substrate.

External view
of IC microphone		 Schematic diagram of IC microphone