NL2021071B1

NL2021071B1 - Method for processing an audio signal for a hearing aid

Info

Publication number: NL2021071B1
Application number: NL2021071A
Authority: NL
Inventors: Driebergen Cor
Original assignee: Interhear B V
Priority date: 2018-06-07
Filing date: 2018-06-07
Publication date: 2019-12-13
Also published as: WO2019235913A1

Abstract

During the lifetime of a human his hearing capabilities decline. Humans with impaired hearing may be assisted by a hearing aid to be able to hear others speaking to them. A disadvantage of the current hearing aids is that the intelligibility of users of the hearing aid is still impaired. The intelligibility is improved by a hearing aid according to the invention, comprising: a microphone for receiving an audio signal comprising a speech signal; a low association unit for associating a low frequency range with vowels; a low frequency pass-filter for filtering out a low filtered signal from the audio signal by letting frequencies pass in the low frequency range; a multiplier for multiplying the low filtered signal with an multiplication factor to a multiplied signal; a high association unit associating a high frequency range with consonants; a high frequency pass-filter for filtering out a high filtered signal from the audio signal by letting frequencies pass in the high frequency range; an amplifier for amplifying the high filtered signal with an amplification factor to an amplified signal; a mixer for mixing the multiplied signal and the amplified signal to a mixed audio signal; and a speaker for transmitting the mixed audio signal, wherein the low frequency range is spaced apart from the high frequency range.

Description

FIELD OF THE INVENTION

The invention relates to the field of a method of processing an audio signal. The invention further relates to a hearing aid or mobile device using this method.

BACKGROUND OF THE INVENTION

During the lifetime of a human his hearing capabilities decline. Most of the time this decline goes gradually, but sometimes this decline may be abrupt, such as when a loud noise next to the ear cause ear damage.

Humans with impaired hearing may be assisted by a hearing aid to be able to hear others speaking to them. This allows these humans to continue to participate in society. And as humans are becoming older and older, the ears of these humans will be more and more impaired overtime, thus more and more people will depend on a hearing aid.

In past times the ear trumpet was used to improve the hearing. Nowadays, electronic hearing aids are available having a speaker placed in the ear that outputs an amplified audio signal received by a microphone. Miniaturization has gone such far that the speaker, amplifier, microphone and power source all can be placed in-ear.

A disadvantage of the current hearing aids is that the intelligibility of users of the hearing aid is still impaired.

SUMMARY OF THE INVENTION

An object of the invention is to improve the intelligibility of an audio signal.

According to a first aspect of the invention, a method for processing an audio signal for a hearing-impaired listener comprising a speech signal, wherein the method comprises the steps of:

- receiving the audio signal;

- associating a low frequency range with vowels;

- filtering out a low filtered signal from the audio signal by letting frequencies pass in the low frequency range;

- multiplying the low filtered signal with a multiplication factor to a multiplied signal;

- associating a high frequency range with consonants;

- filtering out a high filtered signal from the audio signal by letting frequencies pass in the high frequency range;

- amplifying the high filtered signal with an amplification factor to an amplified signal;

- mixing the multiplied signal and the amplified signal to a mixed audio signal; and

- transmitting the mixed audio signal;

wherein the low frequency range is spaced apart from the high frequency range.

In most audio models, vowels in speech signals are associated with low frequencies and consonants are associated with high frequencies. Although more detailed models show that some vowels may be associated with high frequencies and some consonants may be associated with low frequencies, still vowels are predominantly associated with low frequencies and consonants are predominantly associated with high frequencies. Independent of the selected model, it is an insight of the inventor that these low and high frequencies ranges should be spaced apart. The technical effect of this insight is that the intelligibility of the mixed audio signal is improved.

The association of vowels and consonants with a particular frequency range may be done based on tests. These tests measure the amount of energy and/or amplitude of a speech signal at a particular frequency. The speech signal comprises a particular vowel or consonant. The particular frequency range for a vowel or consonant is the range of frequencies combined comprising more than a predefined level amount of energy or signal amplitude compared to the total amount of energy or amplitude in the signal. The predefined level may be 50%, 60% or 70%, preferably 80%, more preferably 85%, most preferably 90%. The lower frequency range typically has a lower edge of 100Hz, preferably 125Hz, more preferably 150Hz. The lower frequency range typically has a higher edge of 700Hz, preferably 750Hz, more preferably 800Hz. The higher frequency typically has a lower edge of 1200Hz, preferably 1250Hz, more preferably 1300Hz. The higher frequency typically has a higher edge at a frequency that is on the edge of audibility, such as around 20kHz.

In an embodiment of the invention, the method comprises the steps of associating the low frequency range and associating the high frequency range are based on the language of the speech signal and/or the differences between man and woman. As vowels and consonants are pronounced differently, the association of low and high frequency ranges may be depended on the language or even the dialect of the language. Further, as pronunciation may vary from one person to another and especially pronunciation varies between man and woman, the association of low and high frequency ranges may vary. In a further embodiment of the invention, the steps of associating the low frequency range and associating the high frequency range are dynamic. This allows for the method to adapt to changes in the speech signal.

In an embodiment of the method, the amplification factor is higher compared to the multiplication factor, preferably wherein the amplification factor is at least 20dB, preferably 25dB, more preferably 30dB, more preferably 35dB, more preferably 40dB, most preferably 45dB, higher compared to the multiplication factor. Alternatively, in an embodiment of the method, the multiplication factor is in the range of -40dB to 10dB, preferably -35dB to 5dB, more preferably -30dB to OdB, most preferably -25 to -5dB and/or the amplification factor is in the range of -10dB to 25dB, preferably -5dB to 20dB, more preferably OdB to 15dB, most preferably 5 to 10dB. Typically, the hearing impairment gradually develops, whereby the higher frequencies are impaired first or are impaired the most compared to the lower frequencies. Hence, the amplification factor is set higher for higher frequencies.

In an embodiment of the invention, the method comprises the step of receiving the audio signal comprises the step of receiving the audio signal from a microphone and/or the step of transmitting the processed audio signal comprises the step of transmitting the processed audio signal to a speaker.

In an embodiment of the invention, the method comprises the step of attenuating a medium frequency range arranged between the low and the high frequency range. It is an insight of the inventor that attenuating the medium frequency has the effect of enhancing the intelligibility of the speech signal. Typically, this medium frequency range is associated with background noise by the inventor. Thus, the inventor extends the current models of speech with the insight that the frequency ranges associated with vowels and consonants are spaced apart and the frequency range in between is to be attenuated to enhance the intelligibility of the speech signal.

Typically, attenuating the medium frequency typically does not cost energy, on the contrary it saves energy as not the complete frequency spectrum is amplified. Therefore, a further technical effect may be that as the medium frequency range is attenuated, a more energy efficient method is provided for obtaining a more intelligible mixed audio signal from the audio signal.

Preferably, the medium frequency range is centred around the 1kHz. Preferably, the lower edge of the medium frequency range is around the 750Hz and the higher edge is around the 1250Hz. Further preferably, the attenuation of the medium frequency range is at least -20dB, preferably -25dB, more preferably -30dB, most preferably -35dB. This attenuation step may be implemented as a band-stop filter or in software executed on a processor.

In a further embodiment of the invention, the method comprises the step of attenuating all frequencies outside the low and high frequency ranges. The technical effect is that the intelligibility is further enhanced. Furthermore, another technical effect may be that the method becomes even more energy efficient as no energy is wasted due to amplifying frequencies that are not of interest for obtaining a more intelligible mixed audio signal from the audio signal.

According to another aspect of the invention, a computer program product comprising a computer readable medium having computer readable code embodied therein, the computer readable code being configured such that, on execution by a suitable computer or processor, the computer or processor is caused to perform any of the methods according to the claims or specified in the description.

According to another aspect of the invention, a hearing aid for a hearingimpaired listener, comprising:

- a microphone for receiving an audio signal comprising a speech signal;

- a low association unit for associating a low frequency range with vowels;

- a low frequency pass-filter for filtering out a low filtered signal from the audio signal by letting frequencies pass in the low frequency range;

- a multiplier for multiplying the low filtered signal with an multiplication factor to a multiplied signal;

- a high association unit associating a high frequency range with consonants;

- a high frequency pass-filter for filtering out a high filtered signal from the audio signal by letting frequencies pass in the high frequency range;

- an amplifier for amplifying the high filtered signal with an amplification factor to an amplified signal;

- a mixer for mixing the low multiplied signal and the amplified signal to a mixed audio signal; and

- a speaker for transmitting the mixed audio signal, wherein the low frequency range is spaced apart from the high frequency range.

In an embodiment of the invention, a hearing aid, comprising a register for storing a plurality of settings, wherein each setting specifies the amplification or the attenuation for a specific frequency range; wherein a first subset of the plurality of settings forms the low frequency range; and wherein a second subset of the plurality of settings forms the high frequency range. This embodiment provides the advantage of easily setting and changing the amplification or attenuation for a specific frequency. This embodiment further provides the advantage of allowing these settings to be exchangeable between hearing aids having the same or similar frequency ranges for the settings.

According to another aspect of the invention, a mobile device comprising an app for a hearing-impaired listener, comprising:

- an input for receiving an audio signal comprising a speech signal from a microphone;

- a low association unit for associating a low frequency range with vowels;

- a multiplier for multiplying the low filtered signal with a multiplication factor to an amplified signal;

- a high association unit associating a high frequency range with consonants;

- a mixer for mixing the multiplied signal and the amplified signal to a mixed audio signal; and

- an output for transmitting the processed audio signal to a headphone, wherein the low frequency range is spaced apart from the high frequency range.

According to another aspect of the invention, a computer program product comprising a computer readable medium having computer readable code embodied therein, the computer readable code comprising a plurality of settings:

wherein each setting specifies the amplification or the attenuation for a specific frequency range;

wherein a first subset of the plurality of settings forms the low frequency range;

wherein a second subset of the plurality of settings forms the high frequency range; and wherein the computer readable code is configured for use by a hearing aid and/or mobile device according to any of the claims or mentioned in the description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be apparent from and elucidated further with reference to the embodiments described by way of example in the following description and with reference to the accompanying drawings, in which:

Figure 1 schematically shows a hearing aid according to an embodiment of the current invention;

Figure 2 schematically shows a method for processing an audio signal for a hearing-impaired listener;

Figure 3A schematically shows an embodiment of the invention in a first graph;

Figure 3B schematically shows an embodiment of the invention in a second graph;

Figure 4 schematically shows test results of an open ear resonance measurement;

Figure 5 schematically shows settings for an Oticon hearing aid according to the invention;

Figure 6 schematically shows settings for a Phonak hearing aid according to the invention;

Figure 7 schematically shows settings for a Sivantos hearing aid according to the invention;

Figure 8 schematically shows settings for a Starkey hearing aid according to the invention;

Figure 9A schematically shows test results of an intelligibility test for a first listener;

Figure 9B schematically shows test results of an intelligibility test for a second listener;

Figure 9C schematically shows test results of an intelligibility test for a third listener; and

Figure 10 schematically shows an embodiment of a computer program product, computer readable medium and/or non-transitory computer readable storage 5 medium according to the invention.

The figures are purely diagrammatic and not drawn to scale. In the figures, elements which correspond to elements already described may have the same reference numerals.

LIST OF REFERENCE NUMERALS

10	mouth of a speaker
20	ear of a hearing-impaired listener
100	hearing aid
110	audio signal
115	microphone
117	received audio signal
120	low association unit
125	low frequency range settings
130	low frequency pass-filter
135	low filtered signal
140	multiplier
145	multiplied signal
150	frequency register
152	multiplier frequency settings
155	amplifier frequency settings
160	high association unit
165	high frequency range settings
170	high frequency pass-filter
175	high filtered signal
180	amplifier
185	amplified signal
190	mixer
192	mixed audio signal
195	speaker

197	transmitted mixed audio signal
200	method for hearing impaired listener
210	receiving
215	low associating
220	low filtering
225	multiplying
230	high associating
235	high filtering
240	amplifying
245	mixing
250	transmitting
310	first graph
311	low frequency range
312	low frequency gain
315	high frequency range
316	high frequency gain
318	medium frequency
320	second graph
321	low frequency range
322	low frequency gain
325	high frequency range
326	high frequency gain
327	gain peak
328	medium frequency
400	test results of an open ear resonance measurement
410	graph open ear resonance for the left ear
420	open ear resonance for the left ear
450	graph open ear resonance for the right ear
460	open ear resonance for the right ear
500	amplification settings for an Oticon hearing aid
510	table original settings Oticon
520	graph original settings Oticon
522	original settings for “Luid”

524	original settings for “Matig”
526	original settings for “Zacht”
550	table settings according to the invention
560	graph settings according to the invention
562	settings according to the invention for “Luid”
564	settings according to the invention for “Matig”
566	settings according to the invention for “Zacht”
570	dip
600	amplification settings for a Phonak hearing aid
610	table original settings Phonak
620	graph original settings Phonak
622	original settings for “G80”
624	original settings for “G65”
626	original settings for “G50”
650	table settings according to the invention
660	graph settings according to the invention
662	settings according to the invention for “G80”
664	settings according to the invention for “G65”
666	settings according to the invention for “G50”
670	dip
700	amplification settings for a Sivantos hearing aid
710	table original settings Sivantos
720	graph original settings Sivantos
722	original settings for “Loud”
724	original settings for “Medium”
726	original settings for “Soft”
750	table settings according to the invention
760	graph settings according to the invention
762	settings according to the invention for “Loud
764	settings according to the invention for “Medium”
766	settings according to the invention for “Soft”
770	dip
800	amplification settings for a Starkey hearing aid

810	table original settings Starkey
820	graph original settings Starkey
822	original settings for “Luid”
824	original settings for “Matig”
826	original settings for “Zacht”
850	table settings according to the invention
860	graph settings according to the invention
862	settings according to the invention for “Luid”
864	settings according to the invention for “Matig”
866	settings according to the invention for “Zacht”
870	dip
910	first horizontal axis bottom of figure
911	vertical axis
912	second horizontal axis halfway of figure
920	curved line without marking
921	curved line with triangles or circles as markings
922	curved line with squares and crosses as markings
923	curved line with V as markings
924	curved line with T as markings
1000	computer program product
1010	computer readable medium
1020	computer readable code

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following figures may detail different embodiments. Embodiments can be combined to reach an enhanced or improved technical effect. These combined embodiments may be mentioned explicitly throughout the text, may be hint upon in the text or may be implicit.

Figure 1 schematically shows a hearing aid 100 according to an embodiment of the current invention. The hearing aid comprises a microphone 115, a low association unit 120, a low frequency pass filter 130, a multiplier 140, a high association unit 160, a high frequency pass-filter 170, an amplifier 180, a mixer 190 and a speaker 195.

The microphone is arranged for receiving an audio signal 110 for example from the mouth 10 of a speaker. The microphone transforms the audio signal to a received audio signal 117, such as an electrical received audio signal. The received audio signal is distributed to at least the low and high frequency pass-filters. The low and high frequency pass-filters are also provided with low and high frequency range settings 125, 165, respectively. The frequency range settings may comprise a multiplier factor, such as an amplification or an attenuation, per frequency band or range. A range may comprise multiple frequency bands.

The low and high frequency range settings are provided by the low and high association units, respectively. The low frequency range settings are associated with vowels and the high frequency range settings are associated with consonants. The association units may comprise a fixed register with settings. Alternatively, the association unit may comprise an adaptive unit for changing the settings, for example depending on the received audio signal. The adaptation may depend on the language of the received speech signal. The adaptation may depend on the loudness of the received speech signal. The adaptation may depend on the SNR of the audio signal. The adaptation may depend on the presence of background noise in the audio signal. Or the adaptation may depend on a combination of the previous mentioned factors.

The low frequency pass-filter provides a low filtered signal 135 to the multiplier. The hearing aid may further comprise a frequency register 150, which may provide multiplier settings per frequency band 152. Alternatively, the frequency register may provide one multiplier setting 152 for the complete frequency range. In an alternative embodiment the frequency settings are depended on the audio signal in a similar way as for the association units. The multiplier multiplies the low filtered signal with the multiplier setting and provides a multiplied signal 145 to the mixer.

The high frequency pass-filter provides a high filtered signal 175 to the amplifier. The frequency register may provide amplifier settings per frequency band 155. Alternatively, the frequency register may provide one amplifier setting 155 for the complete frequency range. In an alternative embodiment the frequency settings are depended on the audio signal in a similar way as for the association units. The amplifier amplifies the high filtered signal with the amplifier setting and provides an amplified signal 185 to the mixer.

The mixer mixes the multiplied signal and the amplified signal to a mixed audio signal 192. The mixing is typically adding the multiplied signal and the amplified signal, such as adding in the time domain. Alternatively, the adding may be done in the frequency domain. The mixer provides the mixed audio signal to the speaker. The speaker transforms the mixed audio signal in a transmitted mixed audio signal 197, that can be received by an ear 20 of a hearing-impaired listener.

A technical effect of that the low frequency range and the high frequency range is spaced apart is that the intelligibility of the transmitted audio signal is improved. A further technical effect is provided if the frequency range between the low and high frequency range is attenuated. Specific frequency ranges to be amplified and attenuated are detailed throughout this description.

The hearing aid may combine several elements in one element. For example, the low frequency pass-filter may be combined with the multiplier, the high frequency pass-filter may be combined with the amplifier, the low association unit and the high association unit may be combined, the low and high frequency pass-filter may be combined making the mixer implicit and/or the low and high association units may be combined with the frequency register. Furthermore, part of the signals in the hearing aid may be digitized, such as that the filters, association units, multiplier, amplifier and/or mixer are implemented as software run on a microprocessor. In this case the microphone may comprise an AD-converter and/or the speaker may comprise a DA-converter.

Figure 1 can also schematically represent a mobile device by replacing the microphone and speaker with an input and an output, respectively.

Figure 2 schematically shows a method 200 for processing an audio signal for a hearing-impaired listener. The method starts with the step receiving 210 the audio signal. The method continues with the step of associating 215 a low frequency range with vowels. The method continues with the step of filtering 220 out a first low filtered signal from the audio signal by letting frequencies pass in the first low frequency range. The method continues with the step of multiplying 225 the low filtered signal with a multiplication factor to a multiplied signal. The method continues with the step of associating 230 a high frequency range with consonants. The method continuous with the step of filtering 235 out a high filtered signal from the audio signal by letting frequencies pass in the high frequency range. The method continuous with the step of amplifying 240 the high filtered signal with an amplification factor to an amplified signal, the method continuous with the step of mixing 245 the multiplied signal and the amplified signal to a mixed audio signal. The method continuous with the step of transmitting 250 the mixed audio signal. The method further specifies that the low frequency range is spaced apart from the high frequency range. The method provides the technical effects as specified throughout this description.

The different steps in the method described in figure 2 may be executed in a different order, if these steps are independent of each other, depending on the specific embodiment of the method. Also, different steps of the method in figure 2 may be executed in parallel and/or merged depending on the specific embodiment of the method.

Figure 3A and 3B schematically show an embodiment of the invention in a first 310 and second 320 graph, respectively. The graphs have a horizontal axis having a frequency scale in Hertz and a vertical axis having a gain scale in dB. The horizontal axis has a marking 0Hz at its origin.

Further, the horizontal axis has a marking Med. freq. 318, 328, which is an abbreviation of medium frequency. The medium frequency may be extended to either side forming a medium frequency range. The medium frequency or medium frequency range separates a low frequency range 311, 321 from a high frequency range 315, 325.

Further, the vertical axis has a marking OdB indicating no gain. The marking OdB identifies the top of the gain for the low and high frequency range. Alternatively, the top 312, 316, 322, 326 of the gain for the low and high frequency range may be at another level then OdB. Alternatively, the top of the gain for the low and high frequency range are different. Alternatively, the top of the gain for the low and high frequency range are depending on the frequency, such as sloped or curved. Alternatively, figure 3B shows a gain peak or spike 327 in the high frequency range, thus further amplifying the signal for a specific frequency. This last embodiment is specifically advantageous according to the inventor. Settings according to this last embodiment and according to the embodiment in figure 3A are further detailed in figures 5 to 8. Combinations of the alternative embodiments are within the scope of the invention.

Figure 4 schematically shows test results of an open ear resonance measurement 400. This and following test results are print screens of different programs used to provide the reader with insight in the invention. The top graph 410 shows the open ear resonance for the left ear. The bottom graph 450 shows the open ear resonance for the right ear. Both graphs have on the horizontal axis the amplification or attenuation of the ear and on the vertical axis the frequency that is tested. The maximum amplification in the graph is 60dB and the maximum attenuation in the graph is -30dB. The minimum frequency is 125Hz and the maximum frequency is 8kHz.

The line 420 in the top graph shows the ear resonance for the left ear and the line 460 in the bottom graph shows the ear resonance for the right ear. This open ear resonance for the left and right ear are almost always different. This difference allows for directional hearing.

Figure 5 schematically shows settings 500 for an Oticon hearing aid according to the invention. The top table 510 shows the original settings of the Oticon hearing aid. The top graph 520 shows the original settings of the Oticon hearing aid corresponding to the top table. The bottom table 550 shows the settings for the hearing aid according to the invention. The bottom graph 560 shows the settings for the hearing aid according to the invention corresponding to the bottom table.

The tables have different rows representing a frequency band. For each row the centre frequency for the frequency band is shown. The table has different columns with the designation of the column shown at the bottom. The left most column is labelled “Alle” showing the centre frequency. The column to the right is labelled “MPO” which is the abbreviation for Maximum Power Output. The MPO is the maximum power output or amplification factor of the hearing aid. The following columns are labelled “Luid”, “Matig” and “Zacht”, which translate to “Loud”, “Medium” and “Soft”, respectively. Hearing aids typically have amplification settings depending on the loudness of the received audio signal. If the received audio signal is loud, the hearing aid selects the settings for “Luid”, if the received audio signal is soft, the hearing aid selects the settings for “Zacht”, and if the received audio signal is in between or medium, the hearing aid selects the settings for “Matig”.

The graphs 520, 560 show the settings for “Luid”, “Matig” and “Zacht” in the settings tables 510, 550, respectively with three different lines 522, 524, 526, 562, 564, 566 per graph, respectively.

The settings in the bottom table as well as the bottom graph show a dip 570 around the 1 kHz spacing apart and/or separating the lower frequency range below around 750Hz and the higher frequency range above around 1250Hz. This dip suppresses background noise and improves intelligibility according to the invention. This dip may be seen as the medium frequency range.

Figure 6 schematically shows settings 600 for a Phonak hearing aid according to the invention. The top table 610 shows the original settings of the Phonak hearing aid. The top graph 620 shows the original settings of the Phonak hearing aid corresponding to the top table. The bottom table 650 shows the settings for the hearing aid according to the invention. The bottom graph 660 shows the settings for the hearing aid according to the invention corresponding to the bottom table.

The tables have different rows representing a frequency band. For each row the centre frequency for the frequency band is shown. The table has different columns with the designation of the column shown at the bottom. The left most column is labelled “MPO” which is the abbreviation for Maximum Power Output. The MPO is the maximum power output or amplification factor of the hearing aid. The column to the right is labelled “Alle” showing the centre frequency. The following columns are labelled “G80”, “G65” and “G50”. Hearing aids typically have amplification settings depending on the loudness ofthe received audio signal. If the received audio signal is above 80dB, the hearing aid selects the settings for “G80”, if the received audio signal is below 50dB, the hearing aid selects the settings for “G50”, and if the received audio signal is in between or around 65dB, the hearing aid selects the settings for “G65”.

The graphs 620, 660 show the settings for “G80”, “G65” and “G50” in the settings tables 610, 650, respectively with three different lines 622, 624, 626, 662, 664, 666 per graph, respectively.

The settings in the bottom table as well as the bottom graph show a dip 670 around the 1 kHz spacing apart and/or separating the lower frequency range below around 860Hz and the higher frequency range above around 1200Hz. This dip suppresses background noise and improves intelligibility according to the invention. This dip may be seen as the medium frequency range.

Figure 7 schematically shows settings 700 for a Sivantos hearing aid according to the invention. The top table 710 shows the original settings of the Sivantos hearing aid. The top graph 720 shows the original settings of the Sivantos hearing aid corresponding to the top table. The bottom table 750 shows the settings for the hearing aid according to the invention. The bottom graph 760 shows the settings for the hearing aid according to the invention corresponding to the bottom table.

The tables comprise not just values but are represented by settings or sliders of an equalizer. Each slider represents the amplification or attenuation for a specific centre frequency. The values of the sliders are automatically translated in three different settings for “Loud”, “Medium” and “Soft”, respectively of the received audio signal. Hearing aids typically have amplification settings depending on the loudness of the received audio signal. If the received audio signal is loud, the hearing aid selects the settings for “Loud”, if the received audio signal is soft, the hearing aid selects the settings for “Soft”, and if the received audio signal is in between or medium, the hearing aid selects the settings for “Medium”.

The graphs 720, 760 show the settings for “Loud”, “Medium” and “Soft” in the settings tables 710, 750, respectively with three different lines 722, 724, 726, 762, 764, 766 per graph, respectively.

The settings in the bottom table as well as the bottom graph show a dip 770 around the 1 kHz spacing apart and/or separating the lower frequency range below around 750Hz and the higher frequency range above around 1250Hz. This dip suppresses background noise and improves intelligibility according to the invention. This dip may be seen as the medium frequency range.

Figure 8 schematically shows settings 800 for a Starkey hearing aid according to the invention. The top table 810 shows the original settings of the Starkey hearing aid. The top graph 820 shows the original settings of the Starkey hearing aid corresponding to the top table. The bottom table 850 shows the settings for the hearing aid according to the invention. The bottom graph 860 shows the settings for the hearing aid according to the invention corresponding to the bottom table.

The tables have different rows representing a frequency band. For each row the centre frequency for the frequency band is shown. The table has different columns with the designation of the column shown in the middle of the column. The left most column is labelled “Alles” showing the centre frequency. The rightmost column is labelled “MPO” which is the abbreviation for Maximum Power Output. The MPO is the maximum power output or amplification factor of the hearing aid. The columns in between are labelled “Luid”, “Gemiddeld” and “Zacht”, which translate to “Loud”, “Average” and “Soft”, respectively. Hearing aids typically have amplification settings depending on the loudness of the received audio signal. If the received audio signal is loud, the hearing aid selects the settings for “Luid”, if the received audio signal is soft, the hearing aid selects the settings for “Zacht”, and if the received audio signal is in between or average, the hearing aid selects the settings for “Gemiddeld”.

The graphs 820, 860 show the settings for “Luid”, “Gemiddeld and “Zacht” in the settings tables 810, 850, respectively with three different lines 822, 824, 826, 862, 864, 866 per graph, respectively.

The settings in the bottom table as well as the bottom graph show a dip 870 around the 950Hz spacing apart and/or separating the lower frequency range below around 700Hz and the higher frequency range above around 1200Hz. This dip suppresses background noise and improves intelligibility according to the invention. This dip may be seen as the medium frequency range.

Figure 9A, figure 9B and figure 9C schematically shows test results of an intelligibility test for a first, second and third listener, respectively. Reference numbers are only shown for figure 9A but are equally applicable for the figures 9B and 9C.

Intelligibility tests come in different forms, e.g. the speech transmission index, Tikofsky’s 50-word intelligibility test and Harvard PB test. The figures show tests results from the Hearing-Aid Speech Perception Index or HASPI from three different persons. In the measurements set-up the listener was placed in an audio cabin to prevent disturbances from any external audio source. Furthermore, the listener got a headphone on as audio source for the tests.

The first horizontal axis 910 at the bottom of the figure shows the loudness of the test signal in decibels. Although the horizontal axis ranges from -10dB to 120dB, it is clear that measurements are always positive. The vertical axis 911 on the left of the figure shows the percentage of intelligible words. The second horizontal axis 912 halfway of the figure offset to the right relative to the first horizontal axis shows the speech reception index, speech reception test score, speech reception threshold or SRT. The SRT is a score line, which indicates how well the listener understands words or words are intelligible for the listener.

The curved line 920 without marking is the normal line or reference line. The reference is a normal person without hearing problems, thus this line indicates the ideal. The curved line 921 with triangular or circular markings, depending on the figure, are measurements taken with the right ear of the listener without hearing aid. Each marking is a measurement. The curved line 922 with squares and crosses as markings, depending on the figure, are measurements taken with the left ear of the listener without hearing aid. All figures show a considerable gap between the reference line and the curved lines 921, 922 indicating a considerable loss of the capacity of understanding words or intelligibility.

The curved line 923 with V as markings are measurements taken with a free-field stereo measurement. The three figures each show an improvement of the capacity of understanding words or intelligibility for this curved line, but still not close to the reference line.

The curved line 924 with T as markings are measurements taken wherein the listener is equipped with a hearing aid configured according to the invention. This curved line is much closer to the reference line and shows a considerable improvement.

Figure 10 schematically shows an embodiment of a computer program product 1000, computer readable medium and/or non-transitory computer readable storage medium according to the invention.

It should be noted that the figures are purely diagrammatic and not drawn to scale. In the figures, elements which correspond to elements already described may have the same reference numerals.

It will be appreciated that the invention also applies to computer programs, particularly computer programs on or in a carrier, adapted to put the invention into practice. The program may be in the form of a source code, an object code, a code intermediate source and an object code such as in a partially compiled form, or in any other form suitable for use in the implementation of the method according to the invention. It will also be appreciated that such a program may have many different architectural designs. For example, a program code implementing the functionality of the method or system according to the invention may be sub-divided into one or more sub-routines. Many different ways of distributing the functionality among these subroutines will be apparent to the skilled person. The sub-routines may be stored together in one executable file to form a self-contained program. Such an executable file may comprise computer-executable instructions, for example, processor instructions and/or interpreter instructions (e.g. Java interpreter instructions). Alternatively, one or more or all of the sub-routines may be stored in at least one external library file and linked with a main program either statically or dynamically, e.g. at run-time. The main program contains at least one call to at least one of the subroutines. The sub-routines may also comprise function calls to each other. An embodiment relating to a computer program product comprises computer-executable instructions corresponding to each processing stage of at least one of the methods set forth herein. These instructions may be sub-divided into sub-routines and/or stored in one or more files that may be linked statically or dynamically. Another embodiment relating to a computer program product comprises computer-executable instructions corresponding to each means of at least one of the systems and/or products set forth herein. These instructions may be sub-divided into sub-routines and/or stored in one or more files that may be linked statically or dynamically.

The carrier of a computer program may be any entity or device capable of carrying the program. For example, the carrier may include a data storage, such as a

ROM, for example, a CD ROM or a semiconductor ROM, or a magnetic recording medium, for example, a hard disk. Furthermore, the carrier may be a transmissible carrier such as an electric or optical signal, which may be conveyed via electric or optical cable or by radio or other means. When the program is embodied in such a signal, the carrier may be constituted by such a cable or other device or means. Alternatively, the carrier may be an integrated circuit in which the program is embedded, the integrated circuit being adapted to perform, or used in the performance of, the relevant method.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb comprise and its conjugations does not exclude the presence of elements or stages other than those stated in a claim. The article a or an preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Examples, embodiments or optional features, whether indicated as nonlimiting or not, are not to be understood as limiting the invention as claimed.

Claims

EMBODIMENTS:

1. Method for processing (200) an audio signal (110) for a hearing-impaired listener including a speech signal, the method comprising the steps of:

- receiving (210) the audio signal;

- associating (215) a low frequency range with vowels;

- filtering (220) out a low filtered signal from the audio signal by letting frequencies pass in the low frequency range;

- multiplying (225) the low filtered signal with a multiplication factor to a multiplied signal;

- associating (230) a high frequency range with consonants;

- filtering (235) out a high filtered signal from the audio signal by letting frequencies pass in the high frequency range;

- amplifying (240) the high filtered signal with an amplification factor to an amplified signal;

- mixing (245) the multiplied signal and the amplified signal to a mixed audio signal; and

- transmitting (250) the mixed audio signal;

where the low frequency range is spaced apart from the high frequency range.

2. Method according to embodiment 1, associating low and high frequency ranges with vowels and consonants respectively is based on the predominant frequencies of vowels and consonants.

3. Method according to any of the preceding, according to the steps of associating the low frequency range and associating the high frequency range are based on the language of the speech signal and / or the differences between man and woman.

4. Method according to any of the preceding, according to the steps of associating the low frequency range and associating the high frequency range are predetermined or dynamic.

5. Method according to any of the preceding, the amplification factor is higher compared to the multiplication factor, preferably the amplification factor is at least 20dB, preferably 25dB, more preferably 30dB, more preferably 35dB, more preferably 40dB, most preferably 45dB, higher compared to the multiplication factor.

6. Method according to any of the preceding, the multiplication factor is in the range or -40dB to 10dB, preferably -35dB to 5dB, more preferably -30dB to OdB, most preferably -25 to -5dB and / or the amplification factor is in the range of -1 OdB to 25dB, preferably -5dB to 20dB, more preferably OdB to 15dB, most preferably 5 to 10dB.

7. Method according to any of the preceding, according to the method comprising the step of attenuating a medium frequency range arranged between the low and the high frequency range.

8. Method according to embodiment 7, where the medium frequency range is associated with background noise.

9. Method according to any of the 7-8, the attenuation is at least -20dB, preferably -25dB, more preferably -30dB, most preferably -35dB.

10. Method according to any of the preceding, according to the method comprises the step of attenuating all frequencies outside the low and high frequency ranges.

11. Computer program product (1000) including a computer readable medium (1010) having computer readable code (1020) embodied therein, the computer readable code being configured such, on execution by a suitable computer or processor, the computer or processor is caused to perform any of the methods 1-10.

12. Hearing aid (100) for a hearing-impaired listener, including:

- a microphone (115) for receiving an audio signal (110) including a speech signal;

- a low association unit (120) for associating a low frequency range with vowels;

- a low frequency pass filter (130) for filtering out a low filtered signal (135) from the audio signal by letting frequency pass in the low frequency range;

- a multiplier (140) for multiplying the low filtered signal with a multiplication factor to a multiplied signal (145);

- a high association unit (160) associating a high frequency range with consonants;

- a high frequency pass filter (170) for filtering out a high filtered signal (175) from the audio signal by letting frequency pass in the high frequency range;

- an amplifier (180) for amplifying the high filtered signal with an amplification factor to an amplified signal (185);

- a mixer (190) for mixing the multiplied signal and the amplified signal to a mixed audio signal (192); and

- a speaker (195) for transmitting the mixed audio signal, where the low frequency range is spaced apart from the high frequency range.

13. Hearing aid according to claim 12, including a register (150) for disturbance of various settings, including each setting (152, 155) specifies the amplification or the attenuation for a specific frequency range;

where a first subset (152) or the various or settings forms the low frequency range; and waiting a second subset (155) or the various of settings forms the high frequency range.

14. Mobile device including an app for a hearing-impaired listener, including:

- an input for receiving an audio signal including a speech signal from a microphone;

- a low association unit for associating a low frequency range with vowels;

- a low frequency pass filter for filtering out a low filtered signal from the audio signal by letting frequencies pass in the low frequency range;

- a high association unit associating a high frequency range with consonants;

- a high frequency pass filter for filtering out a high filtered signal from the audio signal by letting frequencies pass in the high frequency range;

- an output for transmitting the mixed audio signal to a headphone, where the low frequency range is spaced apart from the high frequency range.

15. Computer program product (1000) including a computer readable medium (1010) having computer readable code (1020) embodied therein, the computer readable code including a variety of settings:

vary each setting specifies the amplification or the attenuation for a specific frequency range;

where a first subset of the multiple of settings forms the low frequency range;

where a second subset of the multiple of settings forms the high frequency range; readable code is configured for use by a hearing aid and / or mobile device according to any of the 12-14.

CONCLUSIONS:

A method of processing (200) an audio signal (110) for a hard-hearing listener comprising a speech signal, the method comprising the steps of:

- receiving (210) the audio signal;

- associating (215) a low frequency range with vowels;

- filtering (220) a low frequency signal from the audio signal by passing frequencies in the low frequency range;

- multiplying (225) the low filtered signal by a multiplication factor to a multiplied signal;

- associating (230) a high frequency range with a consonant;

- filtering (235) a highly filtered signal from the audio signal by passing frequencies in the high frequency range;

- amplifying (240) the high filtered signal with an amplification factor into an amplified signal;

- mixing (245) the multiplied signal and the amplified signal into a mixed audio signal; and

- transmitting (250) the mixed audio signal;

wherein the low frequency range is spaced from the high frequency range.

The method of claim 1, wherein associating the low and high frequency ranges with vowels and consonants is respectively based on the dominant frequencies of vowels and consonants.

Method according to one of the preceding claims, wherein the steps of associating the low frequency range and associating the high frequency range are based on the language of the speech signal and / or the differences between men and women.

A method according to any one of the preceding claims, wherein the steps of associating the low frequency range and the high frequency range are determined in advance or dynamically.

Method according to any of the preceding claims, wherein the gain factor is higher compared to the multiplication factor, preferably wherein the gain factor is at least 20dB, preferably 25dB, more preferably 30dB, more preferably 40dB, most preferably 45dB, higher then the multiplication factor.

A method according to any one of the preceding claims, wherein the multiplication factor is in the range of -40dB to 10dB, preferably -35dB to 5dB, more preferably -30dB to OdB, most preferably -25 to -5dB and / or the gain factor is in the range of -10dB to 25dB, preferably -5dB to 20dB, more preferably OdB to 15dB, most preferably 5 to 10dB.

A method according to any one of the preceding claims, wherein the method comprises the step of attenuating a middle frequency range arranged between the low and high frequency ranges.

The method of claim 7, wherein the middle frequency range is associated with background noise.

The method according to claims 7-8, wherein the attenuation is at least -20dB, preferably -25dB, more preferably -30dB, most preferably -35dB.

The method of any one of the preceding claims, wherein the method comprises the step of attenuating all frequencies outside the low and high frequency ranges.

A computer program product (1000) comprising a computer readable medium (1010) with computer readable code (1020) embedded therein, the computer readable code being configured such that, upon execution on a suitable computer or processor, the computer or processor is one of performs the methods 110.

A hearing aid (100) for a hearing-impaired listener, comprising:

- a microphone (115) for receiving a sound signal comprising a speech signal;

- a low frequency pass filter (130) for filtering a low frequency signal from the sound signal by passing frequencies in the low frequency range;

- a multiplier (140) for the low filtered signal with a multiplication factor to a multiplied signal (145);

- a high association unit (160) for associating a high frequency range with a consonant;

- a high frequency pass filter (170) for filtering a high filtered signal from the sound signal by passing frequencies in the high frequency range;

- an amplifier (180) for amplifying the high-filtered signal with an amplification factor to an amplified signal (185);

- a mixer (190) for mixing the multiplied signal and the amplified signal into a mixed audio signal (192); and

- an audio speaker (195) for transmitting the mixed audio signal, wherein the low frequency range is spaced from the high frequency range.

The hearing aid of claim 12, comprising a register (150) for storing a plurality of settings, wherein each setting (152, 155) specifies the gain or attenuation for a specific range;

wherein a first subset (152) of the plurality of settings forms the low frequency range; and wherein a second subset (155) of the plurality of settings forms the high frequency range.

A mobile device comprising an application for a hearing impaired person, comprising:

- an input for receiving a sound signal comprising a speech signal from a microphone;

- an output for sending the mixed audio signal to headphones, wherein the low frequency range is spaced from the high frequency range.

A computer program product (1000) comprising a computer readable medium (1010) with computer readable code (1020) embedded therein, the computer readable code comprising a plurality of settings:

where each institution is the reinforcement or weakening of a specific

Specify frequency range;

wherein a second subset of the plurality of settings forms the high frequency range; and

10 wherein the computer readable code is configured for use by a hearing aid and / or mobile device according to any of claims 12-14.

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