Here are some notes i took while comparing the features and audio quality on four Android audio recording applications I just tested on my LG Revolution phone.
The good news is that with a high quality recording app, the microphone on the LG Revolution turns out to be quite good. Mono, of course.
========== Audio Recording Apps ==== High quality voice and music recording RecForge (Lite/Pro) Folder/File selection is on main screen By default records to SD Card: G:\RecForge\*.wav, *.mp3 after first installation If you navigate elsewhere, it will record there. If you quit from the menu and reenter, it will return to where you were located in previous session, and record there unless you cd WAV, MP3, or OGG formats Sample rates of 8, 11, 22, or 44 kHz 16b Mono/Stereo Good capture of highs/sibilants Very good quality with either mp3 or wav Mono MP3 is 485KB/31sec: 16KB/sec Can auto convert WAVs to MP3, optionally deleting WAV Lite limits the time of compressed recordings Cons: ~three second load time Pros: .WAV capable Folder structure is explicit in the UI. Hi-Q MP3 (Lite) MP3, bit rates of 128 (CD), 96, 64, or 32 (voice) kbps Records to Recordings folder on SD card Internal G:/Recordings/*.mp3 .MP3 file/codec (high quality 44kHz sampling available) 633KB/40sec: 16KB/sec Good capture of highs/sibilants Very good quality with mp3 Pros: Instant load time (but dialog for free version must be dismissed) Input gain control (“experimental”) Cons: Record button-to-record delay: about 2 seconds on first recording Doesn’t offer an uncompressed format Little or no control of where recording files are put. ==== Voice recording – low quality, loss of sibilants and highs Rehearsal Assistant Compressed, or WAV Records to Internal G:\urbanstew.RehearsalAssistant Configural Email default settings Projects .3GP file/codec Some loss of highs/sibilants Very small file: Mono, 68KB/22sec ~= 3KB/sec VoiceRecorder (Preloaded on my LG Revolution) AMR (use AVS Audio Converter or the like on PC to convert) Records to either internal memor or SD card SD Card F:/my_sounds/*.amr Some added warble/vibrato Loss of highs/sibilants .AMR file/codec
============ AMR audio info
Source: http://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_codec
• Sampling frequency 8 kHz/13-bit (160 samples for 20 ms frames), filtered to 200–3400 Hz.
• The AMR codec uses eight source codecs with bit-rates of 12.2, 10.2, 7.95, 7.40, 6.70, 5.90, 5.15 and 4.75 kbit/s.
• Generates frame length of 95, 103, 118, 134, 148, 159, 204, or 244 bits for bit rates 4.75, 5.15, 5.90, 6.70, 7.40, 7.95, 10.2, or 12.2 kbit/s, respectively
• AMR utilizes Discontinuous Transmission (DTX), with Voice Activity Detection (VAD) and Comfort Noise Generation (CNG) to reduce bandwidth usage during silence periods
