Audio output device and control method

An audio output device includes a voltage detection unit, a processing unit, a voltage detection unit, an alarm unit and an audio output unit. The voltage detection unit is utilized for detecting a voltage level of an audio signal to generate a detection result. The processing unit is utilized for determining whether the voltage level of the audio signal is greater than a threshold value according to the detection result and accordingly generating a control signal. The volume adjustment unit is utilized for adjusting the audio signal to generate an adjusted audio signal according to the control signal. The alarm unit is utilized for outputting a first alarm signal to implement an alarm function according to the control signal. Then audio output unit is utilized for playing the adjusted audio signal according to the control signal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an audio output device and a control method, and more particularly, to an audio output device and a control method capable of adjusting volume of an audio signal and performing alarm functions.

2. Description of the Prior Art

With rapid development of technology, portable electronic devices equipped with multimedia playback functions, such as wearable devices, smart phones, notebooks, tablets, portable audio players, are widely used in the daily life. In general, audio signals can be generated by the portable electronic devices and played back via external audio output devices.

However, the portable electronic device may output an audio signal in an inappropriate volume level since the portable electronic device does not offer proper volume control for the audio signal. So, a user may feel uncomfortable due to a sound of large volume and even suffer from hearing loss or hearing impairment. For example, if a portable audio player provides audio signals at very high volume. As the user wears a pair of headphones and the pair of headphones is connected to the portable audio player, the audio signals may be passed on to the pair of headphones and played at high volume level accordingly. Under such a situation, the user would listen to the audio signal too loud and suffer hearing loss. Thus, the prior art has to be improved.

SUMMARY OF THE INVENTION

It is therefore an objective of the present invention to provide an audio output device and a control method capable of adjusting volume of an audio signal and performing alarm functions for preventing hearing loss.

The present invention provides an audio output device, comprising: a voltage detection unit for detecting a voltage level of an audio signal to generate a detection result; a processing unit for determining whether the voltage level of the audio signal is greater than a threshold value according to the detection result and accordingly generating a control signal; a volume adjustment unit for adjusting the audio signal to generate an adjusted audio signal according to the control signal; an alarm unit for outputting a first alarm signal to implement an alarm function according to the control signal; and an audio output unit for playing the adjusted audio signal according to the control signal.

The present invention further provides a control method for an audio output device, comprising: receiving an audio signal from an audio generating apparatus when the audio output device is connected to the audio generating apparatus; detecting a voltage level of the audio signal to generate a detection result; determining whether the voltage level of the audio signal is greater than a threshold value according to the detection result and accordingly generating a control signal; adjusting the audio signal to generate an adjusted audio signal according to the control signal; outputting a first alarm signal to implement an alarm function according to the control signal; and playing the adjusted audio signal according to the control signal.

DETAILED DESCRIPTION

Please refer toFIG. 1, which is a schematic diagram of an audio output device10according to an embodiment of the present invention. The audio output device10may be a headphone or a speaker, and is not limited herein. The audio output device10includes an audio input unit102, a voltage detection unit104, a processing unit106, a volume adjustment unit108, an alarm unit110and an audio output unit112. The audio input unit102is utilized for receiving an audio signal SA when the audio output device10is connected to an audio generating apparatus (not shown in figures). The voltage detection unit104is utilized for detecting a voltage level of the audio signal SA to generate a detection result. The processing unit106is utilized for determining whether the voltage level of the audio signal SA is greater than a threshold value TH according to the detection result and generating a control signal SC accordingly, so as to control operations of the volume adjustment unit108, the alarm unit110and/or the audio output unit112. The volume adjustment unit108is utilized for adjusting the audio signal SA to generate an adjusted audio signal SA′ according to the control signal SC. The audio output unit112is utilized for playing the audio signal SA or adjusted audio signal SA′ according to the control signal SC. The alarm unit110is utilized for outputting alarm signals to implement alarm functions according to the control signal SC.

In brief, when the audio output device10of the invention connects to the audio generating apparatus and receives the audio signal, the audio output device10can detect the volume level of the audio signal and control the volume of the audio signal to fall within an appropriate level range to prevent hearing loss.

For an illustration of the operations of the audio output device10, please refer toFIG. 2.FIG. 2is a flow diagram of a procedure20according to an embodiment of the present invention. The flowchart inFIG. 2mainly corresponds to the operations on the audio output device10shown inFIG. 1. According to the procedure20, the user can utilize the audio output device10shown inFIG. 1to play audio signals transmitted from an audio generating apparatus. In Step202, the audio output device10connects to an audio generating apparatus, wherein the audio output device10may connect to the audio generating apparatus in a wired and/or wireless manner. After that, the audio input unit102receives the audio signal SA from the audio generating apparatus. In Step204, the voltage detection unit104detects a voltage level of the audio signal SA and accordingly generates a detection result.

In an embodiment, the audio output device10has volume control permission when the audio output device10receives audio signals. In Step206, the processing unit106determines whether the voltage level of the audio signal SA is greater than a threshold value TH according to the detection result of Step204and generates a control signal SC accordingly, to control operations of the volume adjustment unit108, the alarm unit110and/or the audio output unit112. In other words, the processing unit106can compare the voltage level of the audio signal SA with the threshold value TH, so as to generate the control signal SC.

In Step208, when the control signal SC indicates that the audio output device10has the volume control permission and the voltage level of the audio signal SA is greater than the threshold value TH, the volume adjustment unit108adjusts the audio signal SA to generate an adjusted audio signal SA′ according to the control signal SC generated by the processing unit106. For example, the volume adjustment unit108decreases the voltage level of the audio signal SA to generate the adjusted audio signal SA′ for turning down the volume of the audio signal SA and enforcing the volume below a safe level to prevent hearing loss.

Further, the volume adjustment unit108includes a variable resistor unit. The variable resistor unit is utilized for adjusting an independence value according to the control signal SC so that the audio signal SA is adjusted to the adjusted audio signal SA′. For example, when the control signal SC indicates that the audio output device10has the volume control permission and the voltage level of the audio signal SA is greater than the threshold value TH, the variable resistor unit increases the independence value so as to decrease the voltage level of the audio signal SA and accordingly generate the adjusted audio signal SA′, thus turning down the volume of the audio signal.

In Step210, when the control signal SC indicates that the audio output device10has the volume control permission and the voltage level of the audio signal SA is greater than the threshold value TH, the audio output unit112plays the adjusted audio signal SA′ with decreased volume so that hearing impairment can be prevented accordingly. Moreover, when the control signal SC indicates that the audio output device10has the volume control permission and the voltage level of the audio signal SA is greater than the threshold value TH, the alarm unit110outputs a first alarm signal to indicate that the volume of the audio signal SA is above a safe level and the audio output device10is performing a volume adjustment process according to the control signal SC.

In brief, when the audio output device10connects to the audio generating apparatus, the audio output device10has the volume control permission. The audio output device10adjusts the audio signal according to the voltage level of the audio signal and outputs related alarm signals for indicating whether the volume exceeds the safe level and whether the volume adjustment process is performed. As a result, a user will not listen to the audio signal too loud and can be immediately informed of abnormal situations of the audio signal when using the audio output device10.

On the other hand, when the processing unit106determines that the voltage level of the audio signal SA is less than or equal to the threshold value TH (e.g. in Step206and/or Step212), this means that the volume of the audio signal does not exceed a safe level. Therefore, the alarm unit110outputs a second alarm signal according to the control signal SC, to indicate that the current volume of the audio signal does not exceed the safe limit (Step216) and the audio output unit112plays the audio signal SA (Step218). Besides, in Step216, since the volume of the audio signal does not exceed the safe limit, the alarm unit110outputs the second alarm signal, releases the volume control permission and gives the volume control permission to the user. Therefore, the user can adjust the volume of the audio signal at will. For example, the user can control the audio generating apparatus to adjust the volume of the audio signal SA being provided for the audio output unit112.

In an embodiment, after the determination process of Step206and the adjustment process of Step208, the audio output device10may release the volume control permission and continue to monitor the voltage level of the audio signal SA. In Step212, the voltage detection unit104continues to detect voltage levels of the audio signal SA and accordingly generates the detection result. The processing unit106continues to compare the voltage level of the audio signal SA with the threshold value TH according to the detection result and accordingly generates the control signal SC.

In Step214, when the control signal SC indicates that the audio output device10does not has the volume control permission, e.g. the audio output device10has released the volume control permission, and the voltage level of the audio signal SA is greater than the threshold value TH, the alarm unit110outputs a third alarm signal to indicate that the volume exceeds the safe level. In other words, since the audio output device10has released the volume control permission, the audio output device10can indicate that the volume exceeds the safe level via the alarm unit110(Step214). Moreover, the audio output unit112plays the audio signal SA directly (Step218). In Step218, since the audio output device10has released the volume control permission or does not has the volume control permission, the volume control permission can be granted to the user, so that the user can adjust the volume of the audio signal without restraint. For example, the user can control the audio generating apparatus to adjust the volume of the audio signal SA being provided for the audio output unit112.

In brief, when the audio output device10has released the volume control permission or does not has the volume control permission, the audio output device10continues to monitor the voltage level of the audio signal SA and outputs related alarm signals for indicating the current status of the volume of the audio signal.

For example, if the audio output device10is a headphone (or a pair of headphones) and the audio generating apparatus is a portable audio player. The audio output device10has the volume control permission when receiving the audio signal. When an audio plug of the audio output device10connects to an audio jack of the audio generating apparatus, the audio output device10receives the audio signal SA from the audio generating apparatus. The voltage detection unit104detects a voltage level of the audio signal SA and accordingly generates a detection result. The processing unit106determines whether the voltage level of the audio signal SA is greater than a threshold value TH according to the detection result detected by the voltage detection unit104, and generates a control signal SC accordingly. When the control signal SC indicates that the audio output device10has the volume control permission and the voltage level of the audio signal SA is greater than the threshold value TH, the volume adjustment unit108decreases voltage level of the audio signal SA to generate an adjusted audio signal SA′. Under such a situation, the audio output unit112plays the adjusted audio signal SA′ and the alarm unit110may use light emitting diodes (LEDs) to produce yellow light for indicating that the current volume of the audio signal exceeds the safe limit and the audio output device10is performing a volume adjustment process. When the processing unit106determines that the voltage level of the audio signal SA is less than or equal to the threshold value TH, this means that the volume of the audio signal does not exceed the safe limit. Under such a situation, the audio output unit112plays the audio signal SA and the alarm unit110may use LEDs to produce green light for indicating that the current volume of the audio signal does not exceed the safe limit. Therefore, when the user sees the green light generated by the alarm unit110, the user can adjust the volume of the audio signal SA For example, the user can control the audio generating apparatus to adjust the volume of the audio signal SA provided for the audio output unit112. Moreover, the audio output device10may release the volume control permission and continue to monitor the voltage level of the audio signal SA. When the control signal SC indicates that the audio output device10has released the volume control permission and the voltage level of the audio signal SA is greater than the threshold value TH, the alarm unit110may use LEDs to produce red light for indicate that the volume exceeds the safe limit.

Therefore, when having the volume control permission, the audio output device10adjusts the audio signal SA to make the volume of the audio signal fall within a safe level range according to voltage level of the audio signal SA. Moreover, the audio output device10uses LED signals to indicate that whether the current volume of the audio signal exceeds the safe limit. When the user sees the yellow light generated by the alarm unit110, this indicates that the current volume of the audio signal exceeds the safe limit and the audio output device10is performing a volume adjustment process. When the user sees the red light generated by the alarm unit110, this indicates that the current volume of the audio signal exceeds the safe limit and the audio output device10does not perform a volume adjustment process. As such, the user can adjust the volume of the audio signal to turn down the volume. When the user sees the green light generated by the alarm unit110, this indicates that the current volume of the audio signal does exceed the safe limit. The user can adjust the volume of the audio signal without restraint.

The audio output device10ofFIG. 1is an exemplary embodiment of the invention, and those skilled in the art can make alternations and modifications accordingly. For example, the audio generating apparatus can be a wearable device, a head-mounted device, a smart phone, a notebook, a portable audio player or any other device which can generate audio signals. The alarm unit110can be a light emitting device (e.g. an LED device), a speaker or a vibration unit, for informing the user through light, sound, vibration or other alarm signal.

In summary, when the audio output device of the invention connects to an audio generating apparatus, the audio output device can detect the voltage level of the audio signal and control the volume of the audio signal to fall within an appropriate level range for preventing hearing loss. Moreover, the audio output device can output related alarm signals to indicate that whether the volume of the audio signal exceeds the safe level and whether the volume adjustment process is performed, thus notifying abnormal situation of the audio signal for the user immediately.