Even in our days, when the capacity of memory cards is estimated by gigabytes, sometimes it becomes necessary to increase the total length of audio recordings on the medium.
Even more often this problem arises before those who still prefer to use analog tape recorders and dictaphones.
Spend money on a larger memory card. These days their cost is relatively low and for large-scale cards it is sometimes less than 100 rubles per gigabyte.
The audio quality is characterized by twoParameters: the frequency of oversampling and bit depth. Decreasing the first parameter reduces the upper limit of the frequency range, while the second reduces the dynamic range of the recording. However, if the degradation of these characteristics suits you, for example, you are recording a speech, try experimenting with decreasing the values of these parameters.
Use a compressed recording format instead of uncompressed. For example, use MP3 instead of AU or WAV - this will allow you to reduce the file size several times if there is a slight deterioration in quality and keeping the oversampling and bit rate. If the deterioration in quality does not suit you, use the format of "lossless compression" called FLAC. The information contained in the audio file does not change at all, but its volume will only be reduced by a factor of two.
Try to achieve a further reduction in the volume of the audio file by using a more modern compression format, for example, Vorbis OGG or WMA.
On an analog tape recorder or dictaphone,Increase the recording time on the carrier of a given volume by reducing the speed. But remember that playback at reduced speeds is not supported by all devices. Some cassette tape recorders allow to reduce speed from 4.76 to 2.4 cm / s, and reel - from 9.5 to 4.76.
Not all four-track tape recorders and dictaphonesAre stereophonic. The devices, which are simultaneously four-track and monophonic, are quite rare, however, they allow increasing the recording time on one medium (reel or cassette) by half while keeping the speed. But at the same time there is also a problem of compatibility of the produced phonogram with other tape recorders.