GB2331429A

GB2331429A - Ambience-sensitive telephone alerting system

Info

Publication number: GB2331429A
Application number: GB9723908A
Authority: GB
Inventors: Rob Friesen; Blake Owen; Wynn Quon
Original assignee: Mitel Corp
Current assignee: Microsemi Semiconductor ULC
Priority date: 1997-11-12
Filing date: 1997-11-12
Publication date: 1999-05-19
Also published as: GB9723908D0

Abstract

When a call arrives at a telephone, a ringer control and timer 16 causes a sample-and-hold circuit 18 to take a 0.25 second sample of the ambient noise level in the vicinity of the telephone. A gain control 24 sets the gain of a ringer amplifier 26 in dependence on the sampled ambient noise level, so that the ringing signal level produced by a speaker 28 increases as the ambient noise level increases and decreases as the ambient noise level decreases. The gain control 24 may set the gain of amplifier 26 through a look up table of values relating gain to ambient noise level. Alternatively, gain control 24 is programmed to set the ringing output level at a predetermined number of dB over the ambient noise level. The ringing level control system 10 may be a self-contained system integrated on a telephone set, or a stand alone system connected to the telephone set, or may be implemented on a personal computer equipped with a telephone line interface.

Description

r 2331429 AMBIENCE-SENSITIVE ALERTING SYSTEM

FIELD OF THE INVENTION

The present invention relates in general to telephones and more specifically to an ambient noise detection circuit to monitor ambient noise in the vicinity of a telephone and, in response, adjust the level of a ringing signal from the telephone so as to be audible in an area surrounding the telephone.

l o BACKGROUND OF THE INVENTION

Currently, the volume of a telephone ring can only be controlled manually by a subscriber. This gives rise to a number of disturbing scenarios for the subscriber. If a room is very noisy, it is possible that the called subscriber will not hear the ring and thus will miss the opportunity to answer a telephone call. On the other hand, if the room is very quiet, the sudden ringing of the telephone can be very startling.

It is an object of an aspect of this invention to overcome the prior art problems set forth above.

SUNB4ARY OF THE INVENTION According to the present invention, an ambience-sensitive alerting system is provided for automatically adjusting a ringing signal level to compensate for ambient noise in the vicinity of a telephone. The circuit includes: an audio input circuit to sample the ambient noise level and a gain control and a ringer amplifier for increasing the ringing signal level in response to increases in the ambient noise level and decreasing the ringing signal in response to decreases in the ambient noise level.

According to a second aspect of the invention, there is provided a method of adjusting the ringing signal level of a telephone to compensate for ambient noise comprising the steps of.

2 a) detecting an incoming telephone call; b) obtaining an ambient noise level sample; c) producing a ringing signal; d) adjusting the ringing signal according to the ambient noise level sample; and e) outputting the adjusted ringing signal with respect to the ambient noise level sample.

Another aspect of the invention is an improvement to a telephone comprising:

controlling means for detecting the presence of a telephone call and initiating a ringing cycle within the telephone, a ring generator for producing a ringing signal to be used in said ringing cycle, a circuit for automatically adjusting the volume level of the ringing signal to compensate for ambient noise in the vicinity of the telephone, and a speaker to output the ringing signal.

According to an important aspect of the invention, the ambient noise level in the vicinity of a telephone is sampled and that level is used to decrease or increase the 25 volume of the telephone ringing signaL BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described below with reference to the 30 accompanying drawings, in which:

1_--- 3 Figure 1 is a block diagram of a telephone set incorporating the ambience- sensitive alerting system according to the present invention Figure 2 is a schematic illustration of the ambience-sensitive alerting system according to the preferred embodiment; and Figure 3 is a graph showing the relative ring amplifier gains in terms of the ambient noise level.

DETAILED DESCRIPTION OF THE PREFERRED EMBODWENT

Turning to Figure 1, a basic prior art telephone set 1 is shown. A handset 2 is shown with a receiver 3 and a transmitter 4. The handset 2 is connected to a hybrid 5 which, in turn, is connected to a switch hook 6. The switch hook 6 is also connected to a ringer 7 and finally to a telephone Tip and Ring 12. The functionality of the handset, is the hybrid and the switch hook will be well known to persons skilled in the art.

Figure 2 shows the basic circuitry of an ambience-sensitive alerting system 10 according to the present invention, which is preferably implemented within the ringer 7 of telephone set 1. The system 10 examines a sample of an ambient noise level in the vicinity of the telephone set prior to generating a telephone ringing signal in the event of an incoming call, and adjusts the telephone ringing signal to an appropriate level relative to the ambient noise level. The telephone line Tip and Ring 12 is connected to a ring detector 14 which, in nun, is connected to a ringer control and timer 16. A sainple-and-hold circuit 18 is connected to a microphone 20, a gain control 24 and the ringer control and timer 16. The ringer control and timer 16 is further connected to a ringer generator 22. The gain control 24 and the ringer generator 22 are connected to a ringer arnplifier 26. The ringer amplifier 26 is connected to a speaker 28.

The system 10 works in the following manner. When a call arrives from a central office through the telephone line Tip and Ring 12, the ring detector 14 is alerted. After the call is answered, the ring detector 14 alerts the ringer control and timer 16 4 which, in turn, sends a signal to the sample-and-hold circuit 18. The sample-and-hold circuit 18 then proceeds to sample an ambient noise level through the microphone 20 built into the telephone set (Figure 1). The circuit 18 takes a 0.25 second sample and holds it in its memory. After the 0.25 second interval, the ringer control 16 activates the ring generator 22 which, in turn, starts a ringing cycle within the telephone set 1. The sample-and-hold circuit 18 informs the gain control 24 as to the sampled ambient noise level. The gain control 24 signals the ringer amplifier 26 as to the required gain through a predetermined table of values illustrated by Figure 3. The ringer amplifier 26 and the ringer generator 22 then combine to produce an audible output via the io speaker 28 (i.e. start ringing the phone at the selected volume level).

It should be noted that higher ambient noise levels result in louder ringing signal output levels from the speaker 28, and vice versa.

Turning to Figure 3, a representational graph of relative ring amplifier gains in terms of ambient noise levels is shown. It should be noted that the actual gain per ambient noise level is determinable through experimentation.

It will be appreciated that, although only one particular embodiment of the invention has been described and illustrated in detail, various changes and modifications may be made. One such modification is to provide a gain control 24 capable of accepting programmable values. In such an arrangement, the control 24 can be programmed to set the ringing output at a predetermined number of dB over the ambient noise level instead of determining the output level via a standard look up table. Another possible modification is to substitute a suitable audio inputting means for the microphone 20. Likewise, the speaker 28 may be substituted with any suitable audio outputting means. Also, it will be appreciated that the system according to the present invention may be implemented as a self- contained system integrated directly on a telephone set, or as a stand alone system connected to the telephone set. Indeed, the system according to the invention can be implemented on a personal computer system equipped with a telephone line interface. All such changes and modifications may be made without departing from the sphere and scope of the invention as defined by the appended claims.

6

Claims

WE CLAIM:

1. A circuit for automatically adjusting a ringing signal level to compensate for ambient noise in the vicinity of a telephone comprising:

audio inputting means for sampling said ambient noise to provide an ambient noise level sample, and controlling means for increasing said ringing signal level in response to increases in said ambient noise level sample and decreasing said ringing signal level in response to decreases in said ambient noise level sample.

2. The circuit of claim 1 wherein said audio inputting means comprises a microphone and a sampler.

3. The circuit of claim 1 wherein said controlling means comprises:

a gain control connected to said sampler for generating a gain signal proportional to said ambient noise level sample; and a ringer amplifier for receiving said gain signal and, in response, adjusting the volume of said ringing signal level so as to compensate for said ambient noise in the vicinity of said telephone.

4. The circuit of claim 2 wherein said sampler is a sample-and-hold circuit with a minimum storage capacity of 0.25 s for sampling ambient noise level in the vicinity of said telephone.

5. A method of adjusting a ringing signal level of a telephone to compensate for ambient noise comprising the steps of..

a) detecting an incoming telephone call; 7 b) obtaining an ambient noise level sample; c) producing a ringing signal; d) adjusting said ringing signal according to said ambient noise level sample; and e) outputting said ringing signal with respect to said ambient noise level sample.

6. An improvement to a telephone comprising:

controlling means for detecting the presence of a telephone call and initiating a ringing cycle within said telephone, a ring generator for producing a ringing signal to be used in said ringing cycle, a circuit for automatically adjusting volume level of said ringing signal to compensate for ambient noise in the vicinity of said telephone, and a speaker to output said ringing signal.

7. The improvement of claim 6 wherein said controlling means further comprises:

a ring detector for detecting the presence of a telephone call, and a ringer control and timer for initiating a ringing cycle within said telephone.

8. The improvement of claim 6 wherein said ambient noise detection circuit further comprises:

audio inputting means to sample said ambient noise, and 8 controlling means for increasing said ringing signal level in response to increases in said ambient noise level and decreasing said ringing signal level in response to decreases in said ambient noise level.