A voice dialer is software that is often included with newer mobile phones that allows the user to dial a phone number by speaking the number or contact name into the phone. There are actually two software pieces at work in such a process. The first software package recognizes the voice commands and the second package operates the call feature of the telephone.
The technology of the voice dialer has been improved over the years. When phones first started coming out with voice dialers, training was needed. The voice dialer could not intuitively understand what a caller was saying. Therefore, the user was required to speak the names of all contacts, then repeat the name into the phone when voice activation was initiated.
This led to a number of problems. First, training a voice dialer took a substantial amount of time, especially for those who had dozens or hundreds of contacts. Second, the voice dialer was only trained for one person's voice, meaning others could not use the feature on the same phone. Additionally, if a person's voice changed, due to a cold or another condition, the voice dialer oftentimes could no longer recognize the voice, thus requiring the user to "re-train" the software.
The newer voice dialer applications help alleviate those problems by being more intuitive. In fact, nearly anyone can use a voice dialer in a newer phone without any training or problems. Most of those earlier limitations have been overcome, though there still may be some trouble from time to time.
Limitations of the voice dialer include some names that are not phonetically correct. While most dialers are very adept at nuances in the phonetics, there will always be some names that confuse the software. Another problem is organizational contacts that use acronyms. Many times, the voice dialer has a hard time with many consonants together, wanting to pronounce them as a word rather than individually. This is easily remedied by assigning a fictional name to the organization.
Despite these limitations the voice dialer also offers some very good advantages, especially in the area of safety. Jurisdictions which require hands-free devices while talking on a cellular phone make no exception for dialing numbers, which is often more dangerous than any other portion of the call. Therefore, voice dialers may be required in some areas. Also, nearly all voice dialers will offer the opportunity to confirm the contact you are intending to call is the one being called. In some cases, where there is a high degree of certainty, the voice dialer will not ask for confirmation.