Sony PX470, the Digital Voice Recorder has an integrated memory of 4 GB, which equates to a maximum recording time of 59 hours and 35 minutes in stereo mp3 128 kbit/s. You can increase the memory capacity with a micro SD card and get up to 32 GB extra, equating to a recording time of over 536 hours (Micro SD 32 GB, MP3 128 kbits/s). Transferring files to and from your computer is convenient and fast. Plug the ICD-PX470 directly into a USB port for an immediate connection, without a USB cable. The recording names display the date, allowing you to quickly find the files recorded on a specific date. Open the calendar to search by date and find the recording you are looking for. Transcribing conversations in writing is facilitated by the transcription playback mode. Easily go forward or backward in a track, or create markers to help you find your way. Digital amplitude adjustment even allows you to slow down playback speed to listen in detail to the content. Filter out low-frequency background noise when recording. Unwanted noise sources (projectors, traffic or wind) can be filtered to improve voice clarity when listening.