JPH0755550A - Ultrasonic audible device - Google Patents

Abstract

PURPOSE:To enable a man to make an intuitive diagnosis relying on his auditory sense by changing acoustic waves of an ultrasonic frequency band into acoustic waved of an audible frequency band in real time through continuous frequency conversion by a simple means. CONSTITUTION:An ultrasonic audible device is constituted of a microphone 1 which converts acoustic waves containing waves of an ultrasonic frequency band into electric signals, device body 2 which converts acoustic waves of an ultrasonic frequency band into acoustic waves of an audible frequency band based on the output signal of the microphone 1, and earphone 3 which converts the output signal of the device 2 into acoustic waves of an audible frequency band. The device 2 is constituted of a preamplifier section 4 which amplifies the electric signals converted by means of the microphone 1, filter section 5 which only passes the signals of a desired ultrasonic frequency band among the signals amplified by means of the section 4, frequency converting section 6 which changes the acoustic wave signals of the desired ultrasonic frequency band passed through the section 5 into acoustic wave signals of the audible frequency band through frequency-conversion by expanding and contracting the time base, and main amplifier section 7 which amplifies the acoustic wave signals outputted from the section 6 into a prescribed volume.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an ultrasonic audible device,
More specifically, the present invention relates to an ultrasonic audible device applied to various failure diagnosis devices, medical devices, outdoor observation devices, and the like.

[0002]

2. Description of the Related Art Human audible frequency band [20 Hz to 20
Sound waves in the so-called ultrasonic frequency band exceeding KHz] exist widely regardless of the natural world or the non-natural world, but in order to realize the discovery and elucidation of various phenomena based on the sound waves of this kind of ultrasonic frequency band, Attempts have been made to audibly or visualize sound waves in the ultrasonic frequency band including various frequencies. For example, there is an ultrasonic AE method as one method for diagnosing a failure of a mechanical device or the like, but until now, an ultrasonic wave generated at the time of a mechanical failure is converted into an electric signal, and the converted waveform is converted into an oscilloscope or a frequency. It was to visualize and observe with an analyzer.

[0003]

By the way, in order to diagnose a failure by the above-mentioned method, for example, a large-scale device such as an oscilloscope and a frequency analysis device is conventionally required, and real-time diagnosis is difficult. There was a problem that was.

Therefore, the present invention has been proposed in view of the above problems, and an object thereof is to convert a sound wave in the ultrasonic frequency band into a sound wave in the audible frequency band continuously in real time by a simple means. An object is to provide an ultrasonic audible device that can be converted to enable intuitive diagnosis by the human ear.

[0005]

As a technical means for achieving the above object, the present invention AD-converts a sound wave waveform in an ultrasonic frequency band captured by a sound collecting means into digital data at a constant cycle, The digital data is DA-converted at a cycle N times as long as the AD conversion cycle, thereby providing a frequency converter for outputting a sound wave waveform in an audible frequency band in which the time axis of the sound wave waveform is expanded or contracted N times. Is characterized by.

[0006]

In the ultrasonic audible device according to the present invention, by expanding and contracting the time axis of the sound wave waveform in the ultrasonic frequency band, only the frequency of the sound wave waveform is converted to lower the frequency while maintaining the original shape of the sound wave waveform. Alternatively, the frequency can be increased, and it becomes easy to realize real-time continuous frequency conversion of sound waves in the ultrasonic frequency band into sound waves in the audible frequency band.

[0007]

FIG. 1 is a block diagram of an ultrasonic audible device according to the present invention.
2 and will be described.

The ultrasonic audible device of the present invention, as shown in FIG. 1, includes a microphone 1 which is sound collecting means for converting a sound wave including an ultrasonic frequency band into an electric signal, and an electric signal output from the microphone 1. On the basis of a device body 2 that converts a sound wave in the ultrasonic frequency band into an electric signal in the audible frequency band, and an earphone 3 that is a sounding unit that converts the electric signal output from the device body 2 into a sound wave in the audible frequency band. It is roughly composed.

Specifically, the apparatus main body 2 includes a preamplifier section 4 for amplifying the electric signal converted by the microphone 1.
Of the signals amplified by the preamplifier unit 4, a filter unit 5 that allows only a signal in a desired ultrasonic frequency band to pass, and a sound wave of a sound signal in a desired ultrasonic frequency band that passes through the filter unit 5 It is composed of a frequency conversion unit 6 that performs frequency conversion into a sound wave signal in the audible frequency band by expanding and contracting the time axis of the waveform, and a main amplifier unit 7 that amplifies the sound wave signal output from the frequency conversion unit 6 to a predetermined volume. . Although not shown, the device body 2 is provided with a volume or switch for adjusting the volume and setting the sound wave band.

In the ultrasonic audible device having the above structure, first, a sound wave including an ultrasonic frequency band is converted into an electric signal by the microphone 1 and input into the device body 2. In the apparatus body 2, the sound wave signal from the microphone 1 is amplified by the preamplifier unit 4, and then only the sound wave signal in a desired ultrasonic frequency band is selectively passed by the filter unit 5 among the sound wave signals.

The filtered sound wave signal in the ultrasonic frequency band is processed by the frequency converter 6 as follows. That is, when the ultrasonic frequency band is a high frequency band of 20 KHz or more, as shown in FIG. 2, the waveform of the ultrasonic signal a in the ultrasonic frequency band is AD-converted into digital data at a constant cycle.
The time axis of the sound wave waveform is N times [1000 times by converting the digital data by N times the AD conversion cycle by N times (in this case, 1000 times, for example).
Double], the band frequency is 1 / N
The frequency is doubled (1/1000 times) and converted into a sound wave signal b in the audible frequency band with a lower limit of 20 Hz.

However, in the case of this frequency conversion, the sampling time becomes 1 / N of the entire time series, and as a result,
If the sound is constantly sampled at a completely fixed sampling timing, there is a possibility that the sound will be missed when a sound to be converted occurs at a time when it cannot be sampled. Therefore, for example, by sampling under trigger conditions such as amplitude level, it is possible to ensure that the sound to be converted is sampled for the minimum necessary time only when the sound to be converted occurs, without constantly sampling. Can be sampled.

On the contrary, when the ultrasonic frequency band is a low frequency band of 20 Hz or less, the waveform of the ultrasonic wave signal in the ultrasonic frequency band is AD-converted into digital data at a constant cycle, and the digital data is N times the AD conversion cycle. [In this case, for example, 1 /
1000 times] and DA conversion in a cycle of
By reducing the time axis of the sound wave waveform by N times [1/1000 times], the band frequency becomes 1 / N times [1000 times].
Frequency, and converted into a sound wave signal in the audible frequency band with an upper limit of 20 KHz.

In this way, the sound wave signal in the audible frequency band obtained by the frequency conversion unit 6 is amplified by the main amplifier unit 7 to an appropriate volume and then output, and the earphone 3 converts the electric signal into a sound wave. As a result, the sound waves in the audible frequency band that have been frequency-converted from the sound waves in the ultrasonic frequency band can be continuously recognized in real time, and intuitive diagnosis by the human ear is possible.

In the present invention, since only the time axis of the sound wave waveform is expanded or contracted, the output waveform is converted into the low frequency or high frequency by converting only the frequency of the original waveform of the input waveform. Will be things. At this time, by operating the sound wave band setting volume or switch,
By changing the band setting, it is possible to selectively convert a sound wave signal in an arbitrary frequency band into a sound wave signal in an audible frequency band. Further, if the AD conversion and the DA conversion in the frequency conversion unit 6 are continuously performed at the shortest possible time intervals, the sound waves in the ultrasonic frequency band are converted into sound waves in the more natural audible frequency band in real time. To be done.

[0016]

According to the present invention, it is possible to continuously convert a sound wave in the ultrasonic frequency band exceeding the human audible frequency band into a sound wave in the audible frequency band in real time by a simple means. It is possible to convert to sound waves called sound waves in the audible frequency band, and with regard to the discovery and elucidation of various phenomena that use ultrasonic waves as a sound source, the human ear with the ability to distinguish sound colors can be used as it is as a high-performance measuring instrument. Intuitive diagnosis by ear is possible.

Therefore, the device of the present invention can be applied as a diagnostic stethoscope for failure diagnostic equipment, and a diagnostic stethoscope for medical equipment that enables new advanced diagnosis by capturing ultrasonic waves in the body, and ultrasonic waves. It can be applied as a hearing aid for nature observation of field observation equipment for observing living things and natural phenomena as sound sources, and its practical value is great.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an ultrasonic audible device according to the present invention.

FIG. 2 is a waveform diagram for explaining how to frequency-convert a sound wave in the ultrasonic frequency band into a sound wave in the audible frequency band.

[Explanation of symbols]

 1 sound collecting means [microphone] 3 hearing means [earphones] 6 frequency converter

Claims (1)

[Claims] 1. A sound wave waveform in the ultrasonic frequency band captured by a sound collecting means is AD-converted into digital data at a constant cycle, and the digital data is DA-converted at a cycle N times the AD conversion cycle. The time axis of the sound wave waveform is N
An ultrasonic band sound audible device comprising a frequency conversion section for outputting a sound wave waveform in an audible frequency band expanded and contracted by a factor of 2 to a sound means.