Browse Prior Art Database

Musical Instrument Digital Interface Headphones

IP.com Disclosure Number: IPCOM000109982D
Original Publication Date: 1992-Oct-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 3 page(s) / 103K

Publishing Venue

IBM

Related People

Friis, ES: AUTHOR [+2]

Abstract

This article describes an audio headphone unit with built-in circuitry which receives musical instrument digital interface (MIDI) datastream information and converts it directly to audio signals for use on computers or musical instruments with MIDI outputs.

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Musical Instrument Digital Interface Headphones

       This article describes an audio headphone unit with
built-in circuitry which receives musical instrument digital
interface (MIDI) datastream information and converts it directly to
audio signals for use on computers or musical instruments with

MIDI


outputs.

     

MIDI

capability can be easily added to personal computers
through the use of adapter cards.  However, an external sound
processing unit, amplifier, and speakers are generally required to
make use of this ability.  The device disclosed herein combines these
external features into one device.

      Referring to the drawings, Fig. 1 is a diagram of the device.
Fig. 2 is a block diagram of the circuitry within the unit.

      The unit takes the form of a pair of audio headphones.  A cord
connects the headphone unit 1 directly to the

MIDI

output port on the
computer or instrument.  The plug 2 is in the standard MIDI 5-pin DIN
connector form.  Circuitry within the headphone case 3 receives the
MIDI datastream and converts it to an appropriate audio signal, which
is supplied to the user through the headphone speakers 5.  A volume
control 4 is provided.

      The MIDI serial data in arrives at the input of a
Serial-to-Parallel converter 6 (Fig. 2) which converts the MIDI data
into a three-byte word.  The first byte is the status byte, which
describes the type of command, and the second and third bytes are the
data bytes, which contain the command values, such as key numbers and
velocity (loudness) information.  For instance, a Note On command
will have a first byte 9n, where n is the device channel being
addressed (for the headphone application, the channel address may be
ignored), followed by bytes describing the key number (for instance,
60 for Middle C) and the velocity (for a simple implementation
simplification this byte may be ignored).  The presence of a Note On
is decoded by simpl...