| 摘要 |
PURPOSE:To make it possible to transmit various sound informations to a person in water by making the hearing sensation of a person in water the same to that in air, by providing a band-rejection filter with center frequency of 3kHz and inclination of 6dB/oct to the front stage of a power amplifier. CONSTITUTION:The signal oscillated from a signal source 21 is transmitted into water through the frequency characteristic of a band-rejection filter 22 and the transmitting sensitivity frequency characteristic of a piezoelectric type submerged transmitter 24 so as to provide inclination which is 6dB/oct at center frequency of 3kHz or less and 18dB/oct at center frequency of 3kHz or more. By the heating sensation of a person having inclination which is -6dB/oct at center frequency of 3kHz or less and -18dB/oct at center frequency of 3kHz or more, the sound pressure frequency characteristic to an electric signal is flattened. Therefore, the signal from a signal source 21 can be faithfully transmitted to the heating sensation of a person in water. |
