Abstract: The music playing method comprises acquiring an inputted voice, detecting that any one registered character string from among a plurality of registered character strings stored in a recording medium is contained in the voice, and outputting music corresponding to the registered character string after a delay time stored in the recording medium has passed from the time when the voice containing the registered character string is detected in the character string detecting.

Abstract: A rotary tool is provided with a shank and a collar-like section, and further includes a plurality of screw-threaded holes drilled in a vertical end face of the collar-like section, in parallel relationships with the axis of the collar-like section. A plurality of balancing weights are removably screwed in the holes as required to balance the tool.

Abstract: A rotary tool is provided with a shank and a collar-like section, and further includes a plurality of screw-threaded holes drilled in a vertical end face of the collar-like section, in parallel relationships with the axis of the collar-like section. A plurality of balancing weights are removably screwed in the holes as required to balance the tool.

Abstract: The invention relates to a Viterbi decoder for decoding a convolutional code. Branch metrics are normalized, state metrics are calculated from the normalized branch metrics, and the synchronization and asynchronization are determined on the basis of the degree of increase in the calculated state metrics. Thus, the original data can be certainly decoded by a simple hardware without being influenced by the S/N ratio of the communication path.

Abstract: A method of recording a digital data signal, such as an audio PCM signal, onto a recording medium in the longitudinal direction thereof, together with an apparatus which is suitable for this recording method. Even-numbered words and odd-numbered words in a digital data signal are recorded on a first track group and a second track group, respectively, which are separated from each other in the widthwise direction of a recording medium, to prevent a series of words becoming error words because of, for example, a flaw in the recording medium in the longitudinal direction thereof. The data format is changed at the input and output of a recording encoder to enable an error correction code and a recording circuit to be used in common for digital tape recorders which have different numbers of tracks, e.g., n tracks and 2n tracks.