Signal processing method and apparatus for amplifying speech signals

A signal processing apparatus comprising:

• a device, and a memory coupled to the device;
• a first signal extracting unit which extracts a first signal which has a first frequency band from an audio signal including a speech signal;
• a gain generating unit which generates a gain by using a ratio of the speech signal included in the audio signal;
• and
• an extension signal generating unit which generates a second signal which has a second frequency band by using the first signal, the second frequency band not overlapping with the first frequency band, generates a third signal by adding the first signal and the second signal, and applies the gain to the third signal,
• wherein the first signal extracting unit and the gain generating unit are implemented as hardware.

A non-transitory computer-readable recording medium having embodied thereon instructions that, when executed by a computer, causes the computer to perform a signal processing method, the signal processing method comprising:

• extracting a first signal having a first frequency band from an audio signal including a speech signal;
• generating a second signal having a second frequency band by using the first signal, the second frequency band not overlapping with the first frequency band;
• generating a third signal by adding the first signal and the second signal;
• and
• applying a gain, generated by using a ratio of the speech signal included in the audio signal, to the third signal.