JPH0473696A - Sound recording and reproducing device - Google Patents

Abstract

PURPOSE:To keep the sound volume level of reproducing sound constant without attaching an additional circuit by normalizing the sound volume level of sound data stored in a storage means based on a detection result by a sound volume level detecting means. CONSTITUTION:A recording/reproducing machine 1 makes sound into digital data, and records it on sound memory 4 as the sound data Di. A level detector 2 reads out the sound data Di at every prescribed area via the recording/ reproducing machine 1, and detects the maximum level in the area, and outputs it to a normalization processing machine 3 setting it as the maximum level value Dx, and the normalization processing machine 3 performs the normalization of the sound data Di inputted from the recording/reproducing machine 1 based on a prescribed upper limit level value Ds decided in advance and the maximum level value Dx inputted from the level detector 2. In such a way, it is possible to keep the sound volume level constant when the reproduction of recorded sound data is performed.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a voice recording and playback device, and particularly to a voice recording and playback device that writes voice data in a voice synthesis process into a memory etc. during recording, reads it out during playback, and performs voice recording and playback processing. Regarding equipment.

<Prior Art> In a voice recording/playback device, the level of the reproduced voice differs depending on the input level at the time of recording. In particular, when using a voice recording and playback device that uses fixed memory such as a semiconductor, when playing back word voices that have been recorded in isolation under different recording conditions, the level of the reproduced voice varies greatly depending on the word, making it extremely difficult to hear. There are cases. Conventionally, therefore, a countermeasure has been taken in which the amplitude of the input signal is kept constant using an AGC circuit to keep the recorded audio level constant.

<Problems to be Solved by the Invention> However, the conventional method of using an AGC circuit only works when the level of the input audio is within a predetermined range, and it cannot be used for input audio with a level above or below this predetermined range. However, sufficient effects could not be obtained. Furthermore, this method requires an external circuit, which poses a problem of complicating the circuit.

The present invention has been made in view of the above-mentioned conventional problems, and its object is to provide an audio recording and reproducing device that can maintain a constant volume level when reproducing recorded audio data.

Means for Solving the Problems> The present invention has been made to solve the above problems, and includes a storage means for storing audio data, and a volume for detecting the volume level of the audio data stored in the storage means. It is characterized by comprising a level detection means and a volume level normalization means for normalizing the volume level of the audio data stored in the storage means based on the detection result by the volume level detection means.

<Operation> The volume level detection means detects the volume level of the audio data stored in the storage means and outputs it to the volume level normalization means. The volume level normalization means normalizes the volume level of the audio data stored in the storage means based on the output result from the volume level detection means.

<Example> An embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing its configuration.

This audio recording/reproducing device is configured such that input audio is digitized by a recording/reproducing device 1 and temporarily recorded in an audio memory 4 as audio data Di. Thereafter, the audio data Di is read out again by the recording/reproducing device 1, and normalized by the level detector 2 and normalization processor 3, resulting in normalized audio data D1'.
It is configured to be recorded anew into the audio memory 4.

The recording/reproducing device 1 is configured to digitize audio input from a microphone (not shown) and record it in the audio memory 4 as audio data Di.

Further, the recording/reproducing device 1 is configured to read out the audio data Di and output it to the level detector 2 and the normalization processor 3.

The level detector 2 reads the audio data Diti- for each predetermined area via the recording/reproducing device 1, detects the maximum level in the area, and outputs this as the maximum level value DX to the normalization processor 3. It is composed of

The normalization processor 3 normalizes the audio data Di input from the recording/reproducing device 1 based on a predetermined upper limit level value Ds and the maximum level value Dx input from the level detector 2. is configured to do so.

The normalization process in this example is based on equations (1) and (2)
As shown in , the normalization coefficient Kx obtained by dividing the maximum level value Dx by the upper limit level value Ds is
This is done by multiplying i.

Normalization coefficient K x = D x / D s
(1) Normalized audio data Di' = KxXDi
(2) That is, it is configured to perform proportional calculation processing on the audio data Di so that the maximum level value Dx described above becomes a sound having a volume corresponding to the upper limit level value Ds. Then, the normalization processor 3 stores the audio data Di after the normalization process as normalized audio data Di' in the audio memory 4.
The structure is such that it is recorded again. Note that the normalization process is not limited to this calculation method, and may be performed by performing other calculation processes.

The audio memory 4 is composed of a fixed memory such as a semiconductor, and is configured to store digitized audio information. The audio memory 4 can be randomly accessed,
It has a configuration that allows you to read any data at any time.

Next, the operation will be explained.

FIG. 2 is a flowchart showing the operation.

After starting the operation, the recording/reproducing device 1 records the audio data Di in the audio memory 4 (step 60). Then, it is checked in step 61) whether the recording has been completed, and if it has not been completed, the process returns to step 60 to continue the first recording. On the other hand, if the recording and reproducing device 1 has finished, the recording/reproducing device 1 reads the audio data Di from the audio memory 4 and outputs it to the level detector 2. Then, the level detector 2 detects the maximum level in the audio data Dl and outputs this as the maximum level value Dx to the normalization processor 3 (step 62). Normalization processor 3
calculates a normalization coefficient Kx from the maximum level value Dx and the upper limit level value Ds (step 63). Then, the normalization coefficient Kx is used to sequentially normalize the audio data Di input from the recording/reproducing device 1, and the normalized audio data D
1' to level detector 2 (steps 64 and 65).
．． 66), After that, the normalization processor 3 determines whether or not the normalization process has been performed on all n pieces of audio data D1 that are subject to normalization (Step 67), and the unprocessed audio data D1 remains. If so, the process returns to step 65 and continues the normalization process, but if all the audio data D1 has been processed, the operation ends (step 68
).

In this embodiment, the normalization process is performed at the end of the recording operation, but it may also be performed immediately before playback. In addition, the level detector 2 and the normalization processor 3 are connected to the recording/playback device 1.
The audio data Di is directly transferred from the audio memory 4 without going through the
It may be configured to read out.

In the embodiments described above, the volume level of reproduced audio can be made constant without adding any external circuit. Furthermore, the level of input audio to which normalization processing is performed is not limited.

<Effects of the Invention> As explained above, the recording and reproducing apparatus of the present invention includes a storage means for storing audio data, a volume level detection means for detecting the volume level of the audio data stored in the storage means,
and a sound range level normalization means for normalizing the sound range level of the audio data stored in the storage means based on the detection result by the sound volume level detection means, so that reproduction can be performed without adding an external circuit. The audio volume level can be kept constant. Further, the range of input levels on which normalization processing is performed is not limited.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a flowchart showing its operation. 1: Recording/playback device, 2-level detector, 3: Normalization processor, 4: Audio memory, Dl: Audio data, D1': Normalized audio data, DX: Maximum level value, Ds = Upper limit level value, KX: Normalization factor. 1st com

Claims (2)

[Claims] (1) storage means for storing audio data; volume level detection means for detecting the volume level of the audio data stored in the storage means; A sound recording and reproducing device comprising: a volume level normalizing means for normalizing the volume level of the recorded sound data. (2) The volume level of the audio data stored in the storage unit is normalized based on the detection result by the volume level detection unit, and the audio data after normalizing the volume level is returned to the original position of the storage unit. The audio recording and reproducing apparatus according to claim 1, further comprising a volume level normalizing means for storing the volume level in the audio recording and reproducing apparatus.