Sensitivity: (1-9 levels) with higher sensitivity capturing sound from a greater distance and amplifying tiny sounds, but it can also increase environmental noise. Therefore, sensitivity should be adjusted appropriately based on recording distance and environmental conditions. In general, for loud live recordings, reduce sensitivity to eliminate background noise, and for quiet or fluctuating recordings, increase sensitivity while keeping the recorder close to the sound source. Recording Bitrate: indicating the amount of data storage in the recording. The higher the recording bitrate, the better the audio quality, making the recording more realistic, clear, and closer to the original sound, but the encoded file size will be larger; conversely, lower recording bitrates have the opposite effect. Typically, 128Kbps is sufficient. For close-range face-to-face conversations, 48Kbps is adequate; you can adjust it as needed. The default setting for the device is 512Kbps. tip 1 : Battery Life: Different settings and recording formats will affect battery life and storage capacity. Battery life and storage capacity are not the same. [Multi-Functional Applications & Warranty Service] Beyond being a voice recorder, this digital recorder with microphone offers features like A-B repeat playback, timed recording, and an MP3 player. It even includes password settings for added security. With a 24-month quality guarantee and 24-hour response after-sales service, it's a reliable choice for college lectures and more. [Voice-Activated Recording] When the voice recorder is in a low or silent state, voice-activated recording will automatically stop recording, saving battery life or storage space. This can improve efficiency, reduce resource consumption, and make the recording process more automated and intelligent. [1100h Long Battery Life] Supports approximately 20 hours of continuous recording and 34 hours of headphone playback (in power-saving mode with the WAV-512Kbps format, 32-ohm headphone output, and medium volume setting). When connected to an external power source for charging, this handheld recorder can record for about 1100 hours. (storage capacity: mp3-32Kbps format). Plus, it automatically saves recordings when the battery is low, ensuring you don't miss important content. [3072Kbps PCM HD Voice Recorder] Our portable recorder with playback features dual sensitive microphones and a professional recording IC, reducing distortion, intelligent noise reduction, ensuring exceptional sound quality. Whether it's recording music, conference sessions, or college lectures, this digital voice recorders captures every detail with clarity. [Easy to use & Easy Management]This digital audio recorder offers one-touch recording and saving, and easy file management. The 1.77-inch HD color display and intuitive user interface are designed for user-friendliness. The color display provides more details and information, which is very useful for managing recording files, setting device options, and viewing relevant information. Users can easily browse file lists, dates, timestamps, and more.It perfect for lecture recorders for college stude.