The HD-60J is the first jumbo-key amplified phone to offer High-Definition Sound Technology for un-matched voice clarity, making every word vividly sharp, clear and easy to understand, all virtually without any distortion, echo or squealing. It also offers —off-hook" warnings to alert you that you've not reset the handset properly and thus unknowingly blocking all incoming calls. It also features the advanced Digital Tone Settings that allow you to selectively amplify and enhance the speech frequencies that you can't hear well, making difficult to hear words intelligible and easy to understand again. The HD-60J amplifies the incoming sound up to 600 times louder -- it is ideal for people with weak vision and/or moderate to severe hearing loss and for those who have tried but are not satisfied with other ordinary amplified phones.