日本电信电话公司(NTT)最近开发出手表式简易携带电话机(PHS),其重量为70克,体积为40立方厘米,是目前世界上最小的电话机。这种PHS机采用数字通信方式,喇叭和话筒是合一的。用它打电话,不用拨电话号码。事先可把通话对方的号码、姓名输入机内,最多可输入20个。打电话时只要对话筒呼叫对方的姓名,母机就可通过声音识别装置自动拨号。因此,其操作键 NTT recently developed the PHS, a watch that weighs 70 grams and has a volume of 40 cubic centimeters, making it the world’s smallest telephone. This PHS machine uses digital communications, speakers and microphones are one. Use it to call, do not dial the phone number. You can enter the number and name of the other party in advance. You can enter up to 20 characters. As long as the phone calls each other’s name, the machine can automatically dial through the voice recognition device. Therefore, its operation keys