To increase the volume on the phone, you need to check the Settings of the phone. Some of these phones have a setting related to sound limit (example are the Apple products). Check the settings and make sure that the option is turned off. Once you do this, the volume can be increased to a higher level. This works only when using a handheld device. For the PC part, simply access the sound settings for your sound card and increase the sliders up to 100 %.