Dynamic and adaptive selection of vocabulary and acoustic models based on a call context for speech recognition

#Aspects of the present invention relate to automated-speech processing. Other aspects of the present invention relate to adaptive automatic speech recognition.

#In a society that is becoming increasingly service oriented, choices of products are often determined according to accompanying customer services offered with the products. Companies invest much capital in providing such services in order to attract customers. For example, a customer who purchases a computer from a manufacturer may be provided with a toll free telephone number so that the customer can call for any technical support or service questions. To facilitate offered customer services, a manufacturer may establish a call center equipped with call routing capabilities (e.g., route a call to an available agent), backend database systems managing relevant information such as customer profiles, and personal who are capable of handling different types of questions. There may be other possible system configurations besides call centers that are deployed to facilitate customer services.

#Maintaining a call center is costly. To effectively compete in the market place, the cost associated with customer services has to be kept low. Various strategies of saving cost have been developed. One such strategy is to introduce automatic call routing capability so that there is no need to hire operators whose job is merely direct calls to appropriate agents. Such automatic call routing facilities automatically interpret the needs related to a calling customer (e.g., a customer may have a billing question) and then automatically route the customer's call to an agent who is specialized in the particular domain (e.g., an agent who is responsible for handling billing related questions).

#The present invention is further described in terms of exemplary embodiments, which will be described in detail with reference to the drawings. These embodiments are non-limiting exemplary embodiments, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:

#FIG. 1 depicts a framework in which a caller's speech is recognized using vocabulary and acoustic models adaptively selected based on a call context, according to embodiments of the present invention;

#FIG. 2 depicts the internal high level functional block diagram of a speech recognition mechanism that is capable of adapting its vocabulary and acoustic models to a call context, according to embodiments of the present invention;

#The processing described below may be performed by a properly programmed general-purpose computer alone or in connection with a special purpose computer. Such processing may be performed by a single platform or by a distributed processing platform. In addition, such processing and functionality can be implemented in the form of special purpose hardware or in the form of software being run by a general-purpose computer. Any data handled in such processing or created as a result of such processing can be stored in any memory as is conventional in the art. By way of example, such data may be stored in a temporary memory, such as in the RAM of a given computer system or subsystem. In addition, or in the alternative, such data may be stored in longer-term storage devices, for example, magnetic disks, rewritable optical disks, and so on. For purposes of the disclosure herein, a computer-readable media may comprise any form of data storage mechanism, including such existing memory technologies as well as hardware or circuit representations of such structures and of such data.

#FIG. 1 depicts a framework 100 in which a caller's speech is recognized using vocabulary and acoustic models adaptively chosen based on a call context, according to embodiments of the present invention. Framework 100 comprises a plurality of callers (caller 1 110a, caller 2 110b, . . . , caller n 110c), a voice response system 130, and a speech recognition mechanism 140. A caller communicates with the voice response system 130 via a network 120. Upon receiving a call from a caller via the network 120, the voice response system 140 identifies and forwards information relevant to the call to the speech recognition mechanism 140. Based on such information, the speech recognition mechanism 140 adaptively selects one or more vocabularies and acoustic models, appropriate with respect to the call information and the caller, that are then used to recognize spoken words uttered by the caller during the call.

#A caller may place a call via either a wired or a wireless device, which can be a telephone, a cellular phone, or any communication device, such as a personal data assistant (PDA) or a personal computer, that is capable of transmitting either speech (voice) data or features transformed from speech data. The network 120 represents a generic network, which may correspond to, but not limited to, a local area network (LAN), a wide area network (WAN), the Internet, a wireless network, or a proprietary network. The network 120 is capable of not only transmitting data but also relaying useful information related to the transmission, together with the transmitted data, to the voice response system 130. For example, the network 120 may include switches, routers, and PBXes that are capable of extracting information related to the caller and attaching such information with the transmitted data.