Introduct voice circuitWith the development of society and technology, the modern electronic products design pays great attention to product the easy operational type, the man-machine contact surface certainly to have to be good. The sound, the image and so on make the most important method which associates with the humanity, also is manifested in the electronic products design. Uses a pronunciation chip, lets the product open the mouth to speak, may get up strengthened function and so on propaganda brand, instruction user use, breakdown urgent prompt, entertainment, novel causes the product design to be practical, to forestall opponent by a show of strengthen feats the enemy by a surprise attack. Different product functional design and market demand, when design must correctly select the different pronunciation chip or the module achieves the best natural price ratio. Engineer may from following several aspects consider which kind of type selects the pronunciation chipAfter first, the pronunciation content transcribes the pronunciation chip, whether the content does have frequently to revise: If the pronunciation content frequently must revise, for example, recording greeting card product design and so on the electronic message machine, should use the ISD series or the APR series pronunciation recording and sending out electric circuit, these two kind of chips all support no matter what records, falls thee lectricity pronunciation content not to be able to lose, some 10second -16 minute each kind of different chip may supply the choice. The acoustic fidelity is better, may approach the magnetic tap eacoustic fidelity. If after the pronunciation content reads in does not need to revise, may consider uses OTP (disposable fever to write) the pronunciation electric circuit and to cover the membrane pronunciation electric circuitSecond, how chooses OTP perhaps the MASK pronunciation electric circuit: How these two center selects, then mainly reads the order form the quantity, the variety as well as the date of delivery. After the OTP pronunciation electric circuit must use special-purpose programming fever writing to burn into the pronunciation content edition, needs the PC machine support. This kind of chip not subscribes the quantity limit, a piece also may manufacture, the delivery is quick. Periphery part few, partition simple, the price is lower, at present has 10 second /21 second /42 second /85 second /,170 second /,341 second and so on the many kinds of models to be possible to elect (to be allowed to divide multistage application). Suits must fast promote the product, the batch few, the variety are many, the pronunciation does not have to modify the product selects. On each kind of product and so on electrical appliances, motorcycle, coal gas alarm apparatus, rental car mileage fare meter has obtained the widespread application. If the order form quantity is very big (above 20,000 pieces), request price very low application, like each kind of electronic toy, electronic praying to Buddha machine and so on product, then should use covers the membrane (MASK) the pronunciation electric circuit. At present has 3 second -360 second many kinds of specifications to supply the choice, may divide into the multistage. When MASK chip ordering has to subscribe the quantity and Man Danliang, if throws the single quantity not to be able to achieve for the first time the factory stipulation completely the single quantity, usually also must pay 1500-3000 Dollar light cover to spend (general factory all to pledge throws full stipulation quantity in a year to return light cover to spend). The production cycle is longer, usual need 35-45 day. Throws after the list, is unable to change, the risk is bigger.Third, looks at pronunciation transcribing the length: May see from the above introduction, the ISD/APR monolithic pronunciation recording and sending out chip longest recording time is16 minutes (the 4KHZ sampling rate). In this recording time, uses the ISD/APR chip to have the better natural price ratio. Flows rapidlyBMP5008 multistage recording and sending out board which the company newly promotes, uses the brand-new 32K sampling circuit design, the acoustic fidelity good, may make 4-8 minute multistage recording and sending out, also the price is low, needs the monolithic integrated circuit support not in addition, the suggestion use. If makes a longer time the sound recording (to surpass above 16 minutes), above chip superiority is not obvious, suggested uses flows rapidly companys MP3series general development board and the BSP-60 development board, its acoustic fidelity, the recording length, the easy to operate and the price and so on have the superiority, is longest may achieve for several dozens hours the sound recordings. (These two developments board detailed introduction sees this handbook thread). Fourth, looked the request the pronunciation returns puts the acoustic fidelity: The general pro