Have you even wished that you had a voice recorder when you were visiting with an older relative about your family? Or wanted some way to preserve comments made at a funeral or other family event? In the old days we had to rely on bulky tape recorders that were intrusive and difficult to operate. Tape was expensive and the microphones were large and not very good. Even when the newer cassette recorders were introduced, you still had to make sure the tape was actually moving and that the small microphones weren’t just picking up noise. Today we have tiny digital voice recorders in our smartphones, or more importantly, standalone recorders with remarkably powerful microphones and in a compact size that can easily fit in a pocket or purse.
Like most things digital, voice recorders come with their own set of jargon words. This post is intended to explain how digital voice recorders work, the terminology used in the advertisements online and how to use them to make recordings of family members and events.
What is a digital voice recorder?
It is a device that converts sound, such as speech and other sounds, into a digital file that can be moved from one electronic device to another, played back by a computer, tablet or smartphone and stored like any other digital file. Just as with any digital file, you can send copies to relatives, burn copies to CDs or DVDs and use the audio files as backgrounds to video or slideshow image presentations. For example, you can make a digital recording of your grandmother and then add the digital audio recording as the background to a slide show showing images from her life. Using the proper software tools, digital audio can also be enhanced and edited like any other digital file.
One of the largest markets for digital audio devices is the business world where people use digital audio devices to take notes and dictate letters, memos and other correspondence to assistants for transcribing. The development of digital voice recorders has been significantly influenced by the previous generations of dictating equipment from IBM, Dictaphone and other manufacturers. But today’s electronic digital voice recorders have moved far beyond mere dictation into the world of high-quality sound recording.
If you do a search on Google for digital voice recorders, you might be surprised to see the huge selection of models from dozens of manufacturers. The price spread is simply amazing, from under $10 to over $10,000. There must be some basic differences to reflect such a huge price spread. Before spending any money buying a digital voice recorder, you need to know some basics. I will ignore the very high-end extreme audio equipment to focus on small, hand-held recording devices that cost up to about $600.
All of these compact audio recording devices use flash memory. Some of them use various types of removable memory but some are limited to the built-in memory. Generally, the more expensive models have both built-in memory and the ability to store files on flash memory cards. Most of the voice recorders, no matter what the price, will record a whole days’ worth of recording time. One important feature that is absolutely necessary is the ability to connect the device to a computer to transfer audio files. This feature is present in nearly all the current digital voice recorders, but some of the very inexpensive ones may lack this feature.
My first examples are the Sony Digital Flash Voice Recorder ICD-PX312 for around $50 and the Olympus VN-8100PC Digital Voice Recorder for under $80. Just to give some perspective, Olympus alone has approximately 37 different models of digital voice recorders priced from around $35 to over $500. Here is a link to the specifications for the Sony model and following is a discussion of the relevance and meaning of some of the terms used in advertising:
There are several common file formats for storing audio recordings. The initial distinction is between devices designed to record music and those aimed primarily at an audio market. It may seem obvious that a device designed to record music would work well with voice recording. That may be true, but not necessarily. Some voice recording devices are designed to block out ambient noise which may make for poor music recording quality especially in a live concert. For example, the Sony recorder has this explanation for audio format: Format(s) Supported : MP3 files: Bit Rate: 8 kbps – 192 kbps, VBRSampling Frequencies: 16/22.05/24/32/44.1/48 kHzFile Extension: .mp3.
The reference to the MP3 file type is important; the rest of the specifications are also important and refer to the audio quality. VBR Sampling stands for variable bit rate. This is a little bit complicated and has to do with the MP3 file format. The quality of the sound recorded is achieved by sampling portions of the audio frequencies rather than the entire range of frequencies. The higher the “bit rate” or amount of information recorded, the higher the quality of the recording. But there are parts of the recording that do not need a high bit rate, for example, when there is no sound. The bit rate for these parts of the recording are adjusted so that the overall recording takes less storage space i.e. memory. Because the parts of the recording that have sound are recorded at a higher bit rate, the overall sound quality of the recording is not affected but the size of the file is decreased.
MP3 refers to a form of lossy data compression. This means that not all of the sound is recorded. Parts of the sound outside those necessary for most listeners is discarded, hence only a “sample” of the sound is made. The rest of the information containing the sounds is compressed. MP3 files are, as a result, relatively small, but have a quality that is acceptable for most circumstances. See Wikipedia:MP3. See also Wikipedia:Sound Quality.
The Sony Digital Voice Recorder supports only the MP3 file format. The price difference compared to the Olympus VN-8100PC is reflected in the fact that the Olympus device supports an additional file format, WMA, and has a higher-quality frequency response. The difference means that the lower-priced Sony will do a very adequate job of recording the spoken word, but the Olympus will do a better job with music. WMA file format is a Windows Media Audio file, a data compression file developed by Microsoft. See Wikipedia:WMA Audio.
The more expensive the device the more audio file formats it may support. Some of the other formats are:
- WAV— waveform audio file a standard for IBM and Microsoft
- AIFF– Audio Interchange File Format developed by Apple
- AU— AU audio file format developed by Sun Microsystems.
For most voice only applications, MP3 files are sufficient.
The most basic recorder has a record button, a pause function and an off button. Most of us need a little bit more to make using a digital recorder successful in capturing audio. One consideration, as I mentioned above, is the amount of internal memory and whether or not the device can use external flash memory cards, the same kinds used in cameras. Both the Sony and Olympus models cited above have 2 GBs of internal memory and the Sony comes with a slot for adding memory with a flash memory card. Both recorders have external jacks (connectors) for an external microphone and/or headphones. As with most electronic devices, the features of the more-expensive models migrate into the less-expensive models so that over time, the less-expensive models acquire the features of the more-expensive models. At the same time, the more-expensive models add new features. Most of the voice recorders sold today come with some kind of built-in noise filtering software. This is useful in reducing background noise in large rooms and where there are a lot of echos.
Digital voice recorders do not necessarily become any better as their price increases. You may wish to settle for a reasonable set of features at a reasonable cost and not simply buy the most expensive model.