It's battery number seven.
The line of the point reading wall chart is particularly thin, with a high current battery, a long time will burn the circuit board. That's why the wall charts are being read with a number seven battery.
Speech Recognition technology, also known as Automatic Speech Recognition (ASR), aims to convert the lexical content of human speech into computer-readable input, such as keystrokes, binary codes, or character sequences. Unlike speaker recognition and speaker confirmation, the latter attempts to identify or confirm the speaker who made the speech rather than the lexical content contained therein.