Sound quality metrics (SQMs), such as sharpness and fluctuation strength, are used for objectively evaluating sound quality related to human perception. Recent research has revealed the auditory characteristics, such as the level-dependency and asymmetry, of auditory filter shapes. However, the existing models of the SQMs do not take into account such auditory characteristics. It is unclear whether these models can accurately account for sound quality. This paper proposes computational models of sharpness and fluctuation strength using proposed loudness models composed of the gammatone auditory filterbank and gammachirp auditory filterbank. These two metrics (sharpness and fluctuation strength) for several test signals were calculated using the proposed models then compared with those from perceptual data. The results indicate that the sharpness calculated with the proposed computational models of sharpness was similar to that from the perceptual data on sharpness and was more accurate than the baseline models. Also, the fluctuation strength calculated with the proposed computational models of fluctuation strength was almost similar to that from the perceptual data on fluctuation strength.