價格：免費
更新日期：2018-12-11
檔案大小：1.9M
目前版本：6.0
版本需求：Android 5.0 以上版本
官方網站：http://www.angelfire.com/scifi2/zpt/zptblog.html
Email：fznidarsic@aol.com
聯絡地址：482 Boyer St. Johnstown PA
OVERVIEW
Voice Staff Free is a limited one octave (from base A 220 Hz, to treble A 440 Hz) trial version of Voice Staff Full.
Voice staff can help you to learn how to read the musical staff. Voice Staff inputs sound from the microphone, analyzes the sound, and extracts a frequency. This frequency is then displayed on a musical staff. Voice Staff Full presents three octaves on the musical staff. Voice staff works best with pure sinusoidal tones. Wind instruments such as clarinets and pipe organs produce pure tones. The frequency of these instruments can be interpreted by Voice Staff. String instruments produce distorted wave forms and are difficult to read. The human voice is somewhat readable. The vowel e produces a semi-sine wave and is the most readable.
WOODWINDS
Voice staff reads woodwinds well. Transposed staffs are used with woodwind instruments. Tenor, soprano saxophones, and clarinets
employ transposed staffs. An option is provided to transpose the frequency of Bb instruments up 12.5% to the C instrument staff.
Voice Staff-Full also has an option that transposes the frequency of Eb instruments down 18.8% to the C instrument staff.
YOUR VOICE
Voice Staff can read the voice of clear singers. It may not work well reading your voice.
Sing the scale while saying the vowel e. The lowest note, Do is the key in which you sing. Sing in a high falsetto screeching tone. This tone is a combination of a higher overtone and a fundamental frequency. Voice Staff reads the fundamental frequency. The note that appears is another indication of the key that you sing in.
TECHNICAL DETAILS
Two methods can be used to detect a frequency. They are Fourier Transform and Zero Crossing. Fourier transforms require multiple integrations. They run too slowly and cannot extract every tone on a musical staff in real time. Voice staff uses the zero crossing method. Sound is read from the microphone, digitized, and put into an array. The data is then filtered using a low pass integrating technique. The low pass filter emphasizes the fundamental frequency. The number of times the waveform crosses the X axis is counted and the frequency of the sound is computed.
