The present technique relates to an earhole-wearable sound collection device, a signal processing device, and a sound collection method for realizing sound collection at a high S/N ratio with reduced noise influence, regardless of noise reduction methods such as the SS method.In the earhole-wearable sound collection device, a microphone that collects emitted speech voice is provided in a space that is substantially sealed off from outside and connects to an ear canal of the wearer, so that emitted speech voice propagating through the ear canal of the wearer is collected. A noise cancelling unit that reduces noise propagating in the internal space having the microphone located therein is further provided to improve the S/N ratio of emitted speech voice collection signals. Further, an equalizing process for reducing the muffled sound generated when the emitted speech voice propagating through the ear canal is collected is performed on the sound collection signal from the microphone. In this manner, higher sound quality is achieved.