JPH0494295A - Measuring device for transfer function at head - Google Patents

Abstract

PURPOSE:To measure a transfer function at a head while a passenger takes a seat by providing a microphone to a head rest and correcting a difference from an actual transfer function at the head with a filter. CONSTITUTION:A microphone 2 is provided to a head rest of a seat. Moreover, the output of the microphone 2 is connected to a correction filter 3. When a signal is inputted to a speaker 4, the speaker 4 transduces the signal into a sound and the sound is outputted. The microphone inputs the sound and transduces to an electric signal and outputs it. Furthermore, the output of the microphone 2 is inputted to the correction filter 3, in which a difference from an actual transfer function at a head is corrected and the result is outputted. Thus, while a passenger takes a set, the actual transfer function at the head is measured and a change in the transfer function at the head due to a state change in a cabin is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a head-related transfer function measuring device used for sound field control, etc., which controls a vehicle interior sound field based on a measured head-related transfer function. .

BACKGROUND ART FIG. 2 shows the configuration of a conventional head-related transfer function measuring device. In FIG. 2, 4 is a speaker, and 5 is a dummy head microphone.

Next, the operation of the above conventional example will be explained. In FIG. 2, when a signal is input to the speaker 4, the speaker 4 converts it into sound and outputs it. The dummy head microphone 6 is
It inputs the sound, converts it into an electrical signal, and outputs it. If the input signal of the speaker 4 is the input signal, and the output signals of the dummy head microphone are PL and PR, the transfer functions HL and HR from the speaker input to the dummy head microphone output are HL=PL/I, HR=PR/I. expressed.

In this way, the head related transfer function can also be determined using the conventional head related transfer function measuring device.

Problems to be Solved by the Invention However, the above-mentioned conventional head-related transfer function measuring device has the following problems:
Since the dummy head microphone 5 is used, there is a problem in that it is not possible to measure the head-related transfer function while the passenger is actually sitting on the seat, such as when driving a car. Additionally, measurements cannot be taken if the conditions inside the vehicle change due to the presence of a passenger or luggage.

The present invention solves these conventional problems,
It is an object of the present invention to provide an excellent head-related transfer function measurement device that can measure the head-related transfer function even when a passenger is sitting on a seat or when a change in the conditions inside a vehicle occurs.

Means for Solving the Problems In order to achieve the above object, the present invention provides a microphone in the headrest of the seat, and uses a filter to correct the difference between the transfer function measured by the microphone and the actual head-related transfer function. It is something.

Therefore, according to the present invention, the transfer function is measured with a microphone installed in the headrest of the seat, the transfer function is passed through a filter, and the difference between the filter and the actual head-related transfer function is corrected. This method has the advantage that the actual head-related transfer function can be measured while the passenger is sitting on the seat, and changes in the head-related transfer function due to changes in the conditions inside the vehicle can also be measured.

Embodiment FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a headrest for sorting, and a microphone 2 is provided. 3 is a correction filter to which the output of the microphone 2 is connected. 4 is a speaker.

Next, the operation of the above embodiment will be explained. In the above embodiment, when a signal is input to the speaker 4, the speaker 4
is converted to sound and output. The microphone 2 inputs the sound, converts it into an electrical signal, and outputs it. The output of the microphone 2 is input to a correction filter 3, and the difference with the actual head-related transfer function is corrected and output. If the input signal to the speaker 4 is ■, and the output signals of the microphone 2 are JL and JR, the transfer functions KL and KR from the speaker input to the microphone output are expressed as KL=JL/E and KR=JR/I. . Let the actual head-related transfer functions be HL and HR,
If the transfer function of the correction filter 3 is FL=HL/KL・FR=HR/KR, the transfer functions DL and DR from the speaker input to the filter output are DL=KL −FL=HL・DR−KR″FR=
The HR corresponds to the actual head-related transfer function.

Therefore, first, the head-related transfer functions HL' and HR' are measured using a dummy head microphone using the method shown in FIG. Next, the microphone 2 installed in the headrest 1 is placed in the same state, that is, with the dummy placed.
Measure the transfer functions KLl and KRl up to. Then, based on these transfer functions, FL'=HL'/KL'·FR'-HR'/KR' is calculated, and these FLl and FR' are set as the transfer function of the correction filter 3. In this way, the actual head-related transfer function at that time can be obtained by passing the output of the microphone 2 provided on the headrest 1 through the correction filter.

As a result, even when a passenger is actually seated in the vehicle interior, or a fellow passenger is sitting on the front passenger seat, etc., and luggage is placed, the microphone 2 in the headrest 1 can be
By passing the output through the correction filter 3, the actual head-related transfer function at that time can be measured.

In this way, according to the above embodiment, since the microphone 2 is provided on the headrest 1, there is an advantage that the head-related transfer function can be measured while the passenger is sitting on the seat. Moreover, according to the above embodiment, it is possible to measure a head-related transfer function that changes in accordance with changes in the conditions inside the vehicle interior.

Effects of the Invention As is clear from the above embodiments, the present invention is a system in which a microphone is provided in the headrest, and the difference from the actual head related transfer function is corrected by filtering and adjusting. This has the advantage that the head-related transfer function can be measured while sitting in the chair.

This has the effect of being able to measure a head-related transfer function that changes in accordance with changes in the conditions inside the vehicle.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a head-related transfer function measuring device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a conventional head-related transfer function measuring device. 1... Headrest, 2... Group microphone, 3... Correction filter, 4... Speaker, 6... Dummy Herad microphone.

Claims (1)

[Claims] A head-related transfer function measuring device comprising: a microphone attached to a headrest of a seat and receiving sound from a sound source; and a filter correcting a difference between an output of the microphone and an actual head-related transfer function.