Signal processing apparatus

A signal processing apparatus configured to change volume level or frequency characteristics of an input signal with a limited bandwidth in a first frequency range, the apparatus comprising:

• an ambient noise extracting unit configured to extract ambient noise included in a collection signal, the collection signal collected and limited in band in a second frequency range different from the first frequency range;
• an information extracting unit configured to extract second frequency characteristic information from ambient noise extracted by the ambient noise extracting unit;
• a frequency characteristic information extracting unit configured to estimate first frequency characteristic information from the second frequency characteristic information extracted by the information extracting unit, the first frequency characteristic information including the first frequency range;
• and
• a signal correcting unit configured to change volume level or frequency characteristics of the input signal according to the first frequency characteristic information obtained by the frequency characteristic information extending unit.

A signal processing apparatus comprising:

• an extending unit configured to extend a bandwidth of an input signal limited to a first frequency range, to a fourth frequency range different from the first frequency range;
• an information extracting unit configured to extract third frequency information from a collection signal collected and limited in band in a second frequency range different from the fourth frequency range;
• a frequency characteristic information extending unit configured to estimate fourth frequency characteristic information from the third frequency characteristic information extracted by the information extracting unit, the fourth frequency characteristic information including the fourth frequency range;
• and
• a signal correcting unit configured to change volume level or frequency characteristics of the input signal extended to the fourth frequency range by the extending unit according to the fourth frequency characteristic information obtained by the frequency characteristic information extending unit and the fourth frequency range.