Sound reproduction system and a sound reproduction method

• US 5,617,478 A
• Filed: 04/11/1994
• Issued: 04/01/1997
• Est. Priority Date: 04/11/1994
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Norimatsu, Takeshi, Kawamura, Akihisa, Oda, Mikio, Matsumoto, Masaharu, Serikawa, Mitsuhiko, Numazu, Hiroko, Tagami, Ryou
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Mei, Xu
• Application Number:
  US08/225,602
• Time in Patent Office: 1,086 Days
• Field of Search: 381/1, 381/17, 381/18, 381/61, 381/63, 381/56, 381/49, 381/51-53, 381/86, 381/102, 381/103, 381/104, 395/2.1, 395/2.16-0.19, 395/2.7, 395/2.77, 395/2.34, 395/2.23
• US Class Current: 381/56
• CPC Class Codes: H03G 5/005 of digital signals
• CPC Class Codes: H04R 5/04 Circuit arrangements, e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments combinations of amplifiers H03F3/68; stereophonic systems H04S

Abstract

A sound reproduction system for automatically conducting a tone control for an audio signal according to the present invention includes: an input terminal for inputting an audio signal; a judgment circuit for determining a ratio between a stereophonic signal component and a monophonic signal component of the input audio signal and for outputting a judgment signal; a signal processing section for receiving the input audio signal and processing the input audio signal so as to generate an output signal having uniform transmission characteristics irrespective of the listening position; an adder for receiving the input audio signal and the output signal and for adding the input audio signal with the output signal at a certain addition ratio based on the judgment signal so as to generate an added signal; and a loudspeaker for receiving the added signal and for reproducing the added signal in a plurality of positions.

Claims

1. A sound reproduction system for automatically conducting a tone control and a sound volume adjustment for an audio signal, the sound reproduction system comprising:

input means for inputting an audio signal;

judging means for receiving the input audio signal and for determining whether the input audio signal is a voice signal or a non-voice signal so as to output a judgment signal;

tone control means for adjusting amplitude-frequency characteristics of the input audio signal in accordance with a judgment result by the judgment means and for generating an output signal;

sound volume adjustment means for receiving the output signal and for adjusting sound volume of the output signal in accordance with a tone control conducted by the tone control means;

memory means for storing data of a first amplitude-frequency characteristics pattern for the voice signal, a second amplitude-frequency characteristics pattern for the non-voice signal, and a plurality of amplitude-frequency characteristics patterns gradually shifting from the first amplitude-frequency characteristics pattern to the second amplitude-frequency characteristics pattern, and data of sound volumes corresponding to the respective amplitude-frequency characteristics patterns, wherein

in the first amplitude-frequency characteristics pattern, the amplitudes at lower and higher frequency ranges are lower than the amplitude at a central frequency, and

in the second amplitude-frequency characteristics pattern, the amplitudes at lower and higher frequency ranges are higher than the amplitude at the central frequency;

control means for receiving the judgment signal and controlling the tone control means by generating a control signal for selecting the data of amplitude-frequency characteristics patterns stored in the memory means so as to gradually conduct a tone control at predetermined time intervals until receiving a next judgment signal, and for controlling the sound volume adjustment means by generating a control signal for selecting the data of sound volume stored in the memory means corresponding to the selected data of amplitude-frequency characteristics patterns so as to adjust the sound volume corresponding to respective gradual steps of the tone control; and

output means for receiving the output signal from the sound volume adjusting means and for reproducing the output signal.

2. A sound reproduction method for automatically conducting a tone control and a sound volume adjustment for an audio signal, the sound reproduction method comprising the steps of:

inputting an audio signal;

judging the input audio signal and determining whether the input audio signal is a voice signal or a non-voice signal so as to output a judgment signal;

controlling the tone of the input audio signal by adjusting amplitude-frequency characteristics of the input audio signal based on the judgment signal and generating an output signal;

adjusting the sound volume of the output signal in accordance with a tone control conducted in the step of controlling the tone of the input audio signal;

storing data of a first amplitude-frequency characteristics pattern for the voice signal, a second amplitude-frequency characteristics pattern for the non-voice signal, and a plurality of amplitude-frequency characteristics patterns gradually shifting from the first amplitude-frequency characteristics .pattern to the second amplitude-frequency characteristics pattern, and data of sound volumes corresponding to the respective amplitude-frequency characteristics patterns in memory means, wherein

in the first amplitude-frequency characteristics pattern, the amplitudes at lower and higher frequency ranges are lower than the amplitude at a central frequency, and

in the second amplitude-frequency characteristics pattern, the amplitudes at lower and higher frequency ranges are higher than the amplitude at the central frequency;

receiving the judgment signal and controlling the step of controlling the tone of the input audio signal by generating a control signal for selecting the data of amplitude-frequency characteristics patterns stored in the memory means so as to gradually conduct a tone control at predetermined time intervals until receiving a next judgment signal, and

controlling the step of adjusting the sound volume of the output signal by generating a control signal for selecting the data of sound volume stored in the memory means corresponding to the selected data of amplitude-frequency characteristics patterns so as to adjust the sound volume corresponding to respective gradual steps of the tone control; and

reproducing the output signal.